CRC standard curves and surfaces

CRC STANDARD

CURVES and SURFACES David von Seggern

Boca Raton

CRC Press Ann Arbor London

Tokyo

Library of Congress Cataloging-in-Publication Data

von Seggern, David H. (David Henry) CRC standard curves and surfaces / David Henry von Seggern. p. cm. Updated ed. of: CRC handbook of mathematical curves and surfaces. c1990. Includes bibliographical references and index. ISBN 0-8493-0196-3 1. Curves on surfaces-Handbooks, manuals etc. 1. Von Seggern, David H. (David Henry). CRC handbook of mathematical curves and surfaces. II. Title. QA643.V67 1993 516.3' 52-dc20

92-33596 CIP

This book represents information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. A wide variety of references are listed. Every reasonable effort has been made to give reliable data and information, but the author and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use. Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming, and recording, or by any information storage and retrieval system, without permission in writing from the publisher. Direct all inquiries to CRC Press, Inc., 2000 Corporate Blvd., N.W., Boca Raton, Florida, 33431. © 1993 by CRC Press, Inc.

International Standard Book Number 0-8493-0196-3 Library of Congress Card Number 92-33596 Printed in the United States of America 1 2 3 4 5 6 7 8 9 0 Printed on acid-free paper

PREFACE Mathematical functions are a fundamental and prevalent ingredient in the lendeavors of scientists and engineers. The conclusions, predictions, and analyses of such professionals are most often concisely contained in these abstract relations, which are commonly referred to as "curves" when illustrated. Many special curves can be found in mathematical tables, such as the CRC Handbook of Mathematical Sciences, 1 and in mathematical dictionaries (for example, James and James 2 ). The National Bureau of Standard's handbook (Abramowitz and Stegun3 ) is the acknowledged English-language source for special functions in physics and engineering. The recent work entitled A Catalog of Special Plane Curves 4 is an excellent source for illustrations of interesting functions in two dimensions. Yet, i~ spite of the frequent and widespread use of mathematical functions, there has been, to date, no volume in which a diversity of curves appear in graphic form. Unexpectedly, there is no work which illustrates the spectrum of simple functions found in most integral tables. Thus, there is not a single reference work which draws together the entire gamut of forms which the modern scientist or engineer uses within a career. Such a reference volume is long overdue, especially in light of the fact that "curves" have become the ready tool of many other disciplines due to the computational and storage powers of modern electronic computers. Lastly, most of the curves appearing in older reference works show the imprecision of hand drafting methods, and the reappearance of familiar curves in precise, computer-plotted form should serve a useful purpose in itself. Curves are abstractions of the form and motion of the physical world. Scientists have analyzed this world for millennia in order to render these abstract expressions in the most minute detail, from gross astronomical movements to infinitesimal atomic phenomena. It is now possible for a remarkably detailed synthesis of natural phenomena to be created by the proper use of these abstractions. Some such synthetic renditions have emerged from the field of computer graphics already (mountainous terrain, cloud formations, trees, to name a few) and ,are nearly indistinguishable from reality. Modern scientists' skillful mathematical description of the motion of nature, coupled with modern computing power, has also enabled them to make increasingly accurate predictions of natural events, such as weather, earthquakes, and oceanic currents. All such endeavors involve, as the quantitative basis, functions whose curves are the visual representation of the predicted motion. Scientists and engineers can use this reference work in two ways to aid their work. In the forward manner, they can look up the equation of interest and see the corresponding visual form of the curve. In the inverse manner, they can select a particular curve visually to serve in data fitting or in computer modeling exercises. This handbook, however, purports to serve a larger audience than those engaged in mathematics, science, and engineering. Architects, designers,

draftsmen, and artists should benefit from this reference book of curves. New expressions of form can be imagined through even a casual scanning of the contents of this volume. And if one has general notion of the desired appearance, the appropriate curve can be located in this volume and its mathematical expression noted. The mathematical expressions given here can be readily translated into high-level programming languages (for example, FORTRAN) in order to generate a given curve in a particular environment of application. Recent graphics languages enable cells, segments, or symbols to be created once and stored for future use. These abstractions, which can be composed of one or more curve segments, may be placed in a computer-based design at any scale or rotation angle to achieve the desired effect. The computer revolution indeed makes curve generation easy and rapid and eliminates the former laborious hand calculations necessary to graph even the simplest curves. Achieving the most intricate and subtlest abstract forms, as well as the simple and plain, is possible for those who have only a rudimentary programming knowledge. Properly designed computer programs can open up this possibility even to those who have no grasp of the underlying equations. This work is intended to contain all curves in common use in applied mathematics. In order to be comprehensive, the notion of "curve" has been extended beyond its usual connection with algebraic or transcendental functions. Here "curve" means any line or surface in two or three dimensions which can be generated by a rule or set of rules expressible in mathematical terms. Such rules may be entirely smooth and deterministic, and the first part of this handbook is devoted to the curves represented in this way: algebraic forms, transcendental forms, and special integrals. Here mathematicians, scientists, and engineers will find those curves familiar to them. Selection of functions for curve fitting can be eased by use of this handbook, and questions concerning the form of a given function can be quickly settled. Designers can find curves appropriate to their design goals. The latter part of this handbook comprises curves and surfaces which are not smoothly generated by a single relation, such as piecewise continuous functions, polygons, and polyhedra. When the generating rules include random components, a new series of curves and surfaces emerges-the subject of the final chapter. The need for cataloging such curves is due to the work of Mandelbrot,S who has shown that the study and description of the random component of natural phenomena is as important, if not more important, than that of the deterministic component. A future volume will collect together many interesting and unusual curves which are not normally considered in pure mathematics. These curves will be most useful to artists and designers who are able to employ modern computer-assisted art and drafting systems. This handbook begins with a chapter containing a qualitative summary of deterministic curve properties and a classification of such curves. An explanation of the means and conventions of presentation in later chapters is also

given here. This first chapter is meant to acquaint the reader with fundamental mathematical properties of curves in order that application of the material of the handbook can be more knowledgeable and meaningful. Those with a solid background in calculus will find little new information here. A section on matrix transformations has been included to indicate how a given curve can be made to appear in many different forms. The following chapters are organized so that similar curves are grouped together· for easy reference. Early chapters deal with curves in two dimensions, progressing from the simple to the complex. Later chapters extend the notion of curve to curves and surfaces in three dimensions. Final chapters deal with piecewise continuous functions in two and three dimensions.

REFERENCES 1. Beyer, W. B., Ed., CRC Standard Mathematical Tables, CRC Press, Boca Raton, 1978. 2. James, G., and R. C. James, Eds., Mathematics Dictionary, Van Nostrand, New York, 1949. 3. Abramowitz, M., and I. A. Stegun, Eds., Handbook of Mathematical Functions, National Bureau of Standards, Department of Commerce, Washington, D.C., 1964. 4. Lawrence, J. D., A Catalog of Special Plane Curves, Dover Publications, New York, 1972. 5. Mandelbrot, B. B., The Fractal Geometry of Nature, W. H. Freeman, San Francisco, 1983.

PREFACE TO THE SECOND EDITION Since the publication of the first edition of the CRe Handbook of Mathematical Curves and Surfaces, an extraordinary tool in mathematics has emerged-Mathematica, the work of Stephen Wolfram and Wolfram Research, Inc. Without question, I knew, immediately upon discovering it, that I would prepare a second edition using this program to plot the functions. The plotting capabilities of programs such as Mathematica remove much of the time-consuming work of preparing a volume such as this. All plots of the second edition were done using Mathematica, except those few figures of Chapter 1. In this process, a few minor errors were found in the original version, and two serious errors. More importantly, Mathematica enables this hardbound book to be accompanied by an electronic notebook which may in fact be more useful than the hardbound version. The electronic version is a "dynamic" reference work, while this hardbound version is a "static" one. Only those who have used the Mathematica notebook format can appreciate this fully. The author hopes that those who are using this hardbound version will also have access to the accompanying electronic version. This allows them to redo the plots for the exact parameters of interest and in a style consistent with their needs and preferences. The general content and form of the first edition have been preserved while the number of plotted functions has increased by 30%. An entire new chapter has appeared to show functions of a complex variable. Another new chapter is devoted to curves with a random element, such as autoregressive processes. All the curves of one former chapter entitled "Miscellaneous Curves" have been moved to other chapters where they logically belonged. Several new functions have been added to the chapter on "Special Functions in Mathematical Physics." Several algebraic and transcendental surfaces have been added to the appropriate chapters. In all, nearly every chapter includes significant new contributions. The surface-rendering capabilities of Mathematica were a welcome tool for improving the presentation of the character of the functions over the line rendering used for 3-D in the first edition. The only problem with surface representation is that I had to choose one particular view orientation which best illustrated the surface when, in fact, many different views are really needed. This is, in all cases, a subjective choice. Those with access to the Mathematica notebook version can easily rectify this inflexibility of a hardbound book. Many people have commented on the first edition or suggested new curves to include in a second edition. In this regard, I must especially mention Richard A. Skarda, who sent me a large number of interesting curves, and Oscar L. King, who allowed me to see a collection of curves in the trochoid family. The people at Wolfram Research, Inc. who have kindly helped me were Kevin McIsaacs and Steven Adams.

THE AUTHOR David H. von Seggern, Ph.D., is a geophysicist currently with Phillips Petroleum Company of Bartlesville, Oklahoma. He previously worked for Teledyne Geotech in Alexandria, Virginia, on numerous aspects of underground-nuclear-test detection. During that time, he authored or co-authored numerous professional papers and company reports on the subject. He completed his education at the Pennsylvania State University with a dissertation on earthquake prediction which included an early application of fractal theory in seismology. At Phillips Petroleum Company, Dr. von Seggern has specialized in applying computer graphics to the problems of processing and interpreting seismic data, has promoted seismic modeling as an aid in data interpretation, and has done research in seismic imaging methods using supercomputer technology.

TABLE OF CONTENTS Chapter 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1. Concept of a Curve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1 1.2. Concept of a Surface .................................. 2 1.3. Coordinate Systems ................................... 2 1.3.1. Cartesian Coordinates ........................... 2 1.3.2. Polar Coordinates .............................. 3 1.3.3. Cylindrical Coordinates .......................... 4 1.3.4. Spherical Coordinates ........................... 4 1.4. Qualitative Properties of Curves and Surfaces ................. 5 1.4.1. Derivative .................................... 5 1.4.2. Symmetry .................................... 6 1.4.3. Extent ....................................... 7 1.4.4. Asymptotes ................................... 7 1.4.5. Periodicity .................................... 8 1.4.6. Continuity .................................... 9 1.4.7. Singular Points ................................ 9 1.4.8. Critical Points ................................ 10 1.4.9. Zeros.. .................................... 11 1.4.10. Integrability .................................. 11 1.4.11 Multiple Values ............................... 12 1.4.12 Curvature ................................... 13 1.5. Classification of Curves and Surfaces ...................... 13 1.5.1. Algebraic Curves .............................. 14 1.5.2. Transcendental Curves .......................... 15 1.5.3. Integral Curves ............................... 15 1.5.4. Piecewise Continuous Functions ................... 16 1.5.5. Classification of Surfaces ........................ 16 1.6. Basic Curve and Surface Operations ....................... 17 1.6.1 Translation .................................. 17 1.6.2 Rotation .................................... 17 1.6.3. Linear Scaling ................................ 17 1.6.4. Reflection ................................... 18 1.6.5. Rotational Scaling ............................. 18 1.6.6. Radial Translation ............................. 18 1.6.7. Weighting ................................... 19 1.6.8. Nonlinear Scaling .............................. 19 1.6.9. Shear ...................................... 19 1.6.10. Matrix Method for Transformation ................. 20 1.7. Method of Presentation ................................ 21 1.7.1. Equations ................................... 22 1.7.2. Plots ....................................... 22 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Chapter 2 Algebraic Functions ..................... . ................. 25

2.1. Functions with xn/m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 2.2. Functions with xn and (a + bx)m . . . . . . . . . . . . . . . . . . . . . . . . 30 2.3. Functions with a 2 + x 2 and xm . . . . . . . . . . . . . . . . . . . . . . . . . . 42 2.4. Functions with a 2 - x 2 and xm . . . . . . . . . . . . . . . . . . . . . . . . . . 46 2.5. Functions with a 3 + x 3 and xm . . . . . . . . . . . . . . . . . . . . . . . . . . 50 2.6. Functions with a 3 - x 3 and xm . . . . . . . . . . . . . . . . . . . . . . . . . . 52 2.7. Functions with a 4 + X4 and xm . . . . . . . . . . . . . . . . . . . . . . . . . . 54 2.8. Functions with a 4 - X4 and xm . . . . . . . . . . . . . . . . . . . . . . . . . . 56 2.9. Functions with (a + bX)1/2 and xm . . . . . . . . . . . . . . . . . . . . . . . 58 2.10. Functions with (a 2 - x 2)1/2 and xm . . . . . . . . . . . . . . . . . . . . . . . 66 2.11. Functions with (x 2 - a 2)1/2 and xm . . . . . . . . . . . . . . . . . . . . . . . 70 2.12. Functions with (a 2 + X 2)1/2 and xm . . . . . . . . . . . . . . . . . . . . . . . 74 2.13. Miscellaneous Algebraic Functions ........................ 78 2.14. Algebraic Functions Expressible in Polar Coordinates .......... 88 2.15. Algebraic Functions Expressed Parametrically ................ 94 Chapter 3 Transcendental Functions . . . . . . . . . . . . . . . . . . ................. 97

3.1. 3.2. 3.3. 3.4. 3.5. 3.6. 3.7. 3.8. 3.9. 3.10. 3.11. 3.12. 3.13. 3.14. 3.15. 3.16. 3.17. 3.18.

Trigonometric Functions with sinn(ax) and cosm(bx) (n, m Integers) ...................................... 98 Trigonometric Functions with 1 ± sinn(ax) and 1 ± cosm(bx) . ... 106 Trigonometric Functions with a sinn(c.x) + b cosm(c.x) . . . . . . . . . 112 Trigonometric Functions of More Complicated Arguments ...... 114 Inverse Trigonometric Functions ........................ 118 Logarithmic Functions ................................ 120 Exponential Functions ................................ 124 Hyperbolic Functions ................................ 130 Inverse Hyperbolic Functions ........................... 136 Trigonometric and Exponential Functions Combined .......... 138 Trigonometric Functions Combined with Powers of x ......... 140 Logarithmic Functions Combined with Powers of x ........... 146 Exponential Functions Combined with Powers of x ........... 150 Hyperbolic Functions Combined with Powers of x . ........... 154 Combinations of Trigonometric Functions, Exponential Functions, and Powers of x . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 Miscellaneous Transcendental Functions .................. 158 Transcendental Functions Expressible in Polar Coordinates ..... 164 Parametric Forms ................................... 172

Chapter 4 Polynomial Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

4.1. Orthogonal Polynomials ............................... 184 4.2. Non-orthogonal Polynomials ........................... 194 References ............................................. 198

Chapter 5 Special Functions in Mathematical Physics . . . . . . . . . . . . . . . . . . . . . . 199

5.1. Exponential and Related Integrals ....................... 200 5.2. Sine and Cosine Integrals ............................. 204 5.3. Gamma and Related Functions ......................... 206 5.4. Error Functions .................................... 208 5.5. Fresnel Integrals .................................... 210 5.6. Legendre Functions ................................. 212 5.7. Bessel Functions .................................... 216 5.8. Modified Bessel Functions ............................. 220 5.9. Kelvin Functions .................................... 222 5.10. Spherical Bessel Functions ............................. 226 5.11. Modified Spherical Bessel Functions ...................... 228 5.12. Airy Functions ..................................... 230 5.13. Riemann Functions .................................. 230 5.14. Parabolic Cylindrical Functions ......................... 230 5.15. Elliptic Integrals .................................... 232 5.16. Jacobi Elliptic Functions .............................. 234 References ............................................. 242 Chapter 6 Special Functions in Probability and Statistics ................... 243

6.1. 6.2. 6.3.

Discrete Probability Densities .......................... 243 Continuous Probability Densities ........................ 248 Sampling Distributions ............................... 258

Chapter 7 Three-Dimensional Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261

7.1. Helical Curves ........................... . . . . . . . . . . 262 7.2. Sine Waves in Three Dimensions ........................ 266 7.3. Miscellaneous Spirals ................................ 270 References ............................................. 272 Chapter 8 Algebraic Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 8.1. Functions with ax + by . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274 8.2. Functions with x 2ja 2 ± y2 jb 2 . . . . . . . . . . . . . . . . . . . . . . . . . . 276 8.3. Functions with (x 2ja 2 + y2 jb 2 ± C2)1/2 . . . . . . . . . . . . . . . . . . . 278 8.4. Functions with x 3ja 3 ± y3 jb 3 . . . . . . . . . . . . . . . . . . . . . . . . . . 282 8.5. Functions with x 4ja 4 ± y4jb 4 . . . . . . . . . . . . . . . . . . . . . . . . . . 284

8.6.

Miscellaneous Functions .............................. 286

Chapter 9 Transcendental Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291

9.1. 9.2.

Trigonometric Functions .............................. 292 Logarithmic Functions ................................ 294

9.3. 9.4. 9.5. 9.6.

Exponential Functions ............ : ................... 296 Trigonometric and Exponential Functions Combined .......... 298 Surface Spherical Harmonics ........................... 300 Miscellaneous Transcendental Functions .................. 302

Chapter 10 Complex-Variable Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309

10.1. Algebraic Functions ................................. 310 10.2. Transcendental Functions ............................. 316 Chapter 11 Nondifferentiable and Discontinuous Functions . . . . . . . . . . . . . . . . . . . 323

11.1. 11.2. 11.3.

Functions with a Finite Number of Discontinuities ............ 324 Functions with an Infinite Number of Discontinuities .......... 326 Functions with a Finite Number of Discontinuities in the First Derivative . . . . . . . . . . . . . . . . . ............... 330 11.4. Functions with an Infinite Number of Discontinuities in the First Derivative ................................ 332

Chapter 12 Polygons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337

12.1. Regular Polygons ................................... 338 12.2. Star Polygons ...................................... 338 12.3. Irregular Triangles .................................. 338 12.4. Irregular Quadrilaterals ............................... 340 12.5. Polyiamonds ....................................... 342 12.6. Polyominoes..................... .................. 342 12.7. Polyhexes ......................................... 342 Chapter 13 Polyhedra and Other Closed Surfaces with Edges . . . . . . . . . . . . . . . . . 345

13.1. Regular Polyhedra .................................. 346 13.2. Stellated (Star) Polyhedra ............................. 348 13.3. Irregular Polyhedra .................................. 350 13.4. Miscellaneous Closed Surfaces with Edges ................. 356 References ............................................. 358 Chapter 14 Random Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359

14.1. Elementary Random Processes .......................... 360 14.2. General Linear Processes ............................. 362 14.3. Integrated Processes .............................- .... 372 14.4. Fractal Processes ................................... 378 14.5. Poisson Processes ................................... 380 References ............................................. 382 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383

CRC STANDARD

CURVES and SURFACES

1

Chapter 1

INTRODUCTION 1.1. CONCEPT OF A CURVE Let En be the Euclidean space of dimension n. (According to this definition, E1 is a line, E2 is a plane, and E3 is a volume.) A curve in n-space is defined as the set of points which result when a mapping from E1 to En is performed. In this reference work, only curves in E2 and E3 will be considered. Let t represent the independent variable in E1. An E2 curve is then given by x

=

f( t)

y=g(t)

and an E3 curve by

x=f(t),

y

=

g(t),

z

=

h( t)

where f, g, and h mean "function of." The domain of t is usually (0, 21T), ( - 00,00), or (0,00). These are the parametric representations of a curve. However, in 2-space, curves are commonly expressed as y

=

f( x)

or as

f( x, y)

=

0

which are the explicit and implicit forms, respectively. The explicit form is reducible from the parametric form when x = f(t) = t in 2-space and when x = f(t) = t and y = get) = t in 3-space. The implicit form of a curve will often comprise more points than a corresponding explicit form. For example y2 _ X = 0 has two ranges in y, one positive and one negative, while the explicit form derived from solving the above equation gives y = X 1/ 2 , for which the range of y is positive only. Generally, the definition of a curve imposes a smoothness criterion, 1 meaning that the trace of the curve has no abrupt changes of direction (continuous first derivative). However, for purposes of this reference work, a broader definition of curve is proposed. Here, a curve may be composed of smooth branches, each satisfying the above definition, provided that the intervals over which the curve branches are distinctly defined are contiguous. This definition will encompass forms such as polygons or sawtooth functions.

2

CRC Standard Curves and Surfaces

1.2. CONCEPT OF A SURFACE This reference work will treat only surfaces in 3-space (E3). Therefore a surface is defined as the mapping from E2 to E3 according to x=f(s,t),

Y =g(s,t),

z=h(s,t)

As for curves, the conversion from this parametric form to more common forms z=f(x,y)

or f(x,y,z)=O

may not be possible in some cases. Again, a smoothness criterion 1 is desirable, but the generalized definition of surface requires only that this smoothness criterion be satisfied piecewise for all distinct mappings of the (s, t) plane over which the surface is defined. These generalized surfaces are termed manifolds. Cubes are examples of surfaces which can be defined in this deterministic manner.

1.3. COORDINATE SYSTEMS The number of available coordinate systems for representing curves IS large and even larger for surfaces. However, to maintain uniformity of presentation throughout this volume, only the following will be used: 2-D

3-D

Cartesian, polar

Cartesian, cylindrical, spherical

The term "parametric" is often used as though it were the name of a coordinate system, but it really means a representation of coordinates in terms of an additional independent parameter which is not itself a coordinate of the space En in which the curve or surface exists. 1.3.1. Cartesian Coordinates The Cartesian system is illustrated in Figure 1 for two dimensions. This is the most natural, but not always the most convenient, system of coordinates for curves in two dimensions. Coordinates of a point p are measured linearly along two orthogonal axes which intersect at the origin (0, 0). The Cartesian

3

x

",,,,,,,,,,,,,,,,,,,,,,,,,,,,,.P

I

y

FIGURE 1.

FIGURE 2.

The Cartesian coordinate system for two dimensions.

The Cartesian coordinate system for three dimensions.

system is also called the "rectangular" system. For three dimensions, an additional axis, orthogonal to the other two, is placed as shown in Figure 2. 1.3.2. Polar Coordinates Polar coordinates (r, e) are defined for two dimensions and are a desirable alternative to Cartesian ones when the curve is point symmetric and exists only over a limited domain and range of the variables x and y. As illustrated in Figure 3, the coordinate r is the distance of the point p from the origin, and the coordinate e is the counterclockWise angle which the line from the origin to p makes with the horizontal line through the origin to the right. ClockWise rotations are measured in negative e relative to this line. Transfor-

"7f.~\\ :-

FIGURE 3.

~

The polar coordinate system for two dimensions.

4

CRC Standard Curves and Surfaces

FIGURE 4.

The cylindrical coordinate system for three dimensions.

mations from polar to Cartesian, and vice versa, are made according to x = r cos 8,

Y = r sin 8

8

=

arctan( Y Ix)

1.3.3. Cylindrical Coordinates Cylindrical coordinates are used in three dimensions. They combine the polar coordinates (r,8) of two dimensions with the third coordinate z measured perpendicularly from the (x, y) plane at Cr, 8) to the point p at Cr, 8, z) as in Figure 4. The normal convention is for z to be positive upward. Transformation from cylindrical to Cartesian coordinates involves only the polar-to-Cartesian transformations given above, because the z coordinate is unchanged. Cylindrical coordinates are often appropriate when surfaces are axially symmetric about the z axis, for example, in representing the form r2 = z. 1.3.4. Spherical Coordinates As illustrated in Figure 5, let a point in £3 lie at a radial distance r along a vector from the origin. Project this vector to the (x, y) plane, and let the angle between the vector and its projection be cPo Now measure the angle 8 of the projected line in the (x, y) plane as for polar coordinates. Then (r, 8, cP) are the spherical coordinates of p. The transformations from spherical to Cartesian coordinates, and vice versa, are given by: x

=

r cos 8 sin cP,

y = r sin 8 sin

8 = arctan(Ylx),

cP,

z

=

r cos cP

cP = arctan [ (x 2 + y2) 1/2 Iz ]

5

FIGURE 5. The spherical coordinate system for three dimensions.

Spherical coordinates are often appropriate for surfaces having point symmetry about the origin. The usual coordinates of geography, which refer to points on the earth by latitude and longitude, are a spherical system.

1.4. QUALITATIVE PROPERTIES OF CURVES AND SURFACES Curves and surfaces exhibit a wide variety of forms. Particular attributes of form are derivable from the equations themselves, and many texts treat these in rigorous detail. The purpose here is not to duplicate such explicit and analytical treatment but rather to present the properties of curves and surfaces in a qualitative manner to which their visible forms are naturally and easily related. Understanding of these properties enables one to choose the appropriate curve for a given purpose (for example, data fitting) or to modify, when necessary, an equation given in this volume into one more suitable for a given purpose. 1.4.1. Derivative A fundamental quantity associated with a curve, or function, is the derivative, which exists at all continuous points of the curve (except singular points as described in Section 1.4.7). Although the definition of derivative can be made with analytical rigor,! in graphical terms the derivative at any point is the slope of the tangent line at that point and is written as dy / dx for two-dimensional curves. For three-dimensional curves, the tangent line is along the trajectory of the curve, and three such derivatives are possible using the three pairs of the coordinates x, y, and z. Closely associated with the derivative is a curve's normal, which is the line perpendicular to the tangent. In two dimensions the normal is a single line, but in three dimensions the normal sweeps out a plane perpendicular to the tangent to the curve.

6

CRC Standard Curves and Surfaces

As for curves, the derivative of a surface is a fundamental quantity. The derivative at any continuous point of a surface relates to the tangent plane of the surface at that point. For this plane, three "partial" derivatives exist, written as 3y /oz, oz/ox, and ox/oy (or their inverses), which are the slopes of the lines formed at the intersections of the tangent plane with the (y, z), (z, x), and (x, y) planes, respectively. The normal to the surface at a point is the vector orthogonal to the surface there. It is defined at all points for which the surface is smooth by the partial derivatives

oy Tt oz Tt

OZ

os

ox 8S

oz Tt ox Tt

ox 8S

oy 8S

ox ot oy Tt

j p

using the parametric representation equations. If the surface can be expressed in the implicit form f(x, y, Z) = 0, then simply

The above definitions give the (x, y, Z) components of the normal vector; it is customary to normalize them to (x', y', z') by dividing them with (x 2 + y2 + Z2)1/2 so that X,2 + y,2 + Z,2 = 1. 1.4.2. Symmetry For curves in two dimensions, if y =f(x) =f(-x) holds, then the curve is symmetric about the y axis. The curve is antisymmetric about the y axis if y

=

f(x)

=

-fe -x)

A simple example is powers of x: y = xn. If n is even, the curve is symmetric; if n is odd, it is antisymmetric. Antisymmetry is also referred to as "symmetry with respect to the origin" or "point symmetry" about (x, y) = (0, 0). For surfaces, three kinds of symmetry exist: point, axial, and plane. A surface has point symmetry when Z

= f(x, y) = -f( -x, -y)

Simple examples of point symmetry qre spheres or ellipsoids. A surface has

7

axial symmetry when

z = f(x, y) = f( -x, -y)

An example of axial symmetry is a paraboloid. Finally, a surface has plane symmetry about the (y, z) plane when z=f(x,y) =f(-x,y)

Similarly, symmetry about the (x, z) plane implies z = f(x, y) = f(x, -y) Examples of plane symmetry include z = xy2 and z = eX cos(y). 1.4.3. Extent The extent of a curve is defined by the range (y variation) and domain (x variation) of the curve. The extent is unbounded if both x and y values can extend to infinity (for example, y = x 2 ). The extent is semibounded if either y or x has a bound less than infinity. The transcendental equation y = sin(x) is such a curve, because the range is limited between negative and positive unity. A curve is fully bounded if both x and y bounds are less than infinity. A circle is a simple example of this type of extent. For surfaces the concept of extent can be applied in three dimensions, where "domain" applies to x and y while "range" applies to z. Surfaces formed by revolution of a curve in the (y, z) or (x, z) plane about the z axis will possess the same extent property that the two-dimensional curve had. For example, an ellipse in the (x, z) plane gives an ellipsoid as the surface of revolution-both have the fully bounded property. Similarly, any surface formed by continuous translation of a two-dimensional curve (for example, a parabolic sheet) will have the same extent property as the original curve. 1.4.4. Asymptotes The y asymptotes of a curve are defined by Ya

= lim f(x) x~

±oo

Although this definition includes asymptotes at infinity, only those with

IYa I < 00 are of interest. Asymptotic values are often crucial in choosing and applying functions. Physically, an equation mayor may not properly describe real phenomena, depending on its asymptotic behavior. Note that even though a curve is semibounded, its asymptote may not be determinable. An example of a semibounded function with a y asymptote is y = e-X, while one without an asymptote is y = sin(x).

8

CRC Standard Curves and Surfaces

The x asymptotes of a curve may be defined in a similar manner: xa

=

. lim y-) ±oo

f( y)

when the function is inverted to give x = f(y). An example of a curve with a finite x asymptote is y = (c 2 - X 2 )1/2 , whose asymptotes lie at x = +c and x = -c. In addition, curves may have asymptotes that are any arbitrary lines in the lane, not simply horizontal or vertical lines; and the limit requirements are similar to the forms given above for horizontal or vertical asymptotes. For instance, the equation y = x + Ijx has y = x as its asymptote. 1.4.5. Periodicity A curve is defined as periodic in x with period X if y = f(x

+ nX)

is constant for all integers n. The transcendental function y = sin(ax) is an example of a periodic curve. A polar coordinate curve can also be defined as periodic with period a in terms of angle 0 if

r

=

f(O

+ na)

is constant for all integers n. An example of such a periodic curve is r = cos(40), which exhibits eight "petals" evenly spaced around the origin.

Surfaces are periodic in x and y with periods X and Y, respectively, if z =

f( x + nX, y + mY)

is constant for all integers nand m. A surface also may be periodic in only x or only y. A cylindrical-coordinate surface may be periodic with period a in terms of the angle 0 if

z

=

f( r, 0 + na)

is constant for all integers n. Another type of periodicity expressible cylindrical coordinates is in the radial direction with period R, when

z =f(r

III

+ nR,O)

is constant for all integers n. An example of such periodicity is given by z = cos(2'lTr )cos(O), which has a period of unity in r.

9

1.4.6. Continuity A curve is continuous at a point x o, provided it is defined at x o, when

and y-= lim f(x) X~Xo

are finite and equal. Here "+" and "-" refer to approaching Xo from the right and left, respectively. Discontinuities may be finite or infinite: the former implies y+* y- even though they are both finite, while the latter implies one or both limits are infinite. For surfaces, the paths to a point Po = (x o, Yo) are infinite in number; and continuity exists only if the surface is defined at Po, and z= lim f(p) P->Po

is constant for all possible paths. When the curve or surface is undefined at Xo or Po and the above relations hold, it is said to be discontinuous, but with a removable discontinuity. Also, if the curve or surface is defined at Xo or Po

and the limit exists there but is not equal to the defined value, it has a removable discontinuity there. For any points at which the above relations do not hold, the curve or surface is discontinuous, with an essential discontinuity at such points. The curve y = sin(x)/x has a removable discontinuity at x = 0 and is therefore continuous in appearance, while y = l/x has an essential discontinuity at x = 0 and is therefore discontinuous in appearance. Curves and surfaces are differentiable (meaning the derivative exists) at removable discontinuities. 1.4.7. Singular Points Curves and surfaces of degree 3 or greater may contain singular points. Writing the function for a two-dimensional curve as

f(x,y)=O

the derivative dy / dx can be written as dy dx

g(x, y) hex, y)

where g and h are functions of x and y. If for a given point p(x, y) the functions g and h both vanish, the derivative becomes the indeterminate form 0/0 and p(x, y) is then a singular point of the curve. Singular points imply that two or more branches of the curve meet or cross. If two branches

10

eRC Standard Curves and Surfaces

are involved, it is a double point; if three are involved, it is a triple point; etc. Singularities at triple or higher points are not as commonly encountered as those at double points. Double-point singularities for two-dimensional curves are classified as follows: 1. Isolated (or conjugate) points are single points disjoint from the remainder

of the curve. In this case, the derivative does not exist. 2. Node points are where the two derivatives exist and are unequal, so that the curve crosses itself. 3. Cusp points are where the derivatives of two arcs become equal and the curve ends. A cusp of the first kind involves second derivatives of opposite signs, and a cusp of the second kind involves second derivatives of the same sign. 4. Double cusp (or osculation) points are where the derivatives of two arcs become equal while the two arcs of the curve are continuous along both directions. Double cusps may also be of the first or second kind, like single cusps. Curves having one or more nodes will exhibit loops which enclose areas. Curves having osculations may also exhibit loops, on one or both sides of the osculation point. The concept of singular points is extendable to surfaces. Many surfaces are the result of the revolution of a two-dimensional curve about some line; such surfaces retain the singular points of the curve, except that each such point on the curve, unless on the axis of revolution, becomes a circular ring of singular points centered on the axis of revolution. Singular points appear on more complicated surfaces also, but an analysis of these possibilities is beyond the scope of this volume. 1.4.8. Critical Points Points of a curve y = f(x) at which the derivative dy I dx critical points. There are three types:

=

0 are termed

1. Maximum points are where the curve is concave downward and thus the second derivative d 2 y Idx 2 > O.

2. Minimum points are where the curve is concave upward and thus the second derivative d 2 y Idx 2 < O. 3. Inflection points are where d 2 y Idx 2 = 0 and the curve changes its direction of concavity.

For surfaces z = f(x, y), the critical points lie where ozlox = ozloy = O. Maximum and minimum points of surfaces are defined similarly to those of curves, except both second derivatives must together be greater than zero or less than zero. In the case that they are of opposite sign, the critical point is termed a saddle. Such critical points are nondegenerate 2 and are isolated

11

from other critical points. More complicated types of critical points occur for surfaces and are classified as degenerate or nondegenerate, depending on whether the determinant of

02 Z ox 2 02 Z oX oy

(52 z ox oy 02 Z oy2

vanishes or not. The surface z = x 2 + y2 has a single non degenerate critical point, while z = x 2 y2 has two continuous lines of degenerate critical points, intersecting at (0,0). 1.4.9. Zeros The zeros of a two-dimensional function [(x) occur where y = [(x) = 0 and are isolated points on the x axis. (For polynomial functions, the zeros are often referred to as the roots.) Similarly, the zeros of a three-dimensional function [(x, y) occur where z = [(x, y) = 0, but the locus of these points is one or more distinct, continuous curves in the (x, y) plane. The zeros of certain functions are important in characterizing their oscillatory behavior (for example, the function sin x), while the zeros of other functions may be unique points of interest in physical applications. Not all functions, as defined, have zeros; for example, the function [(x) = 2 - cos x has unity as its lower bound. However, such a function can be translated in one or the other y directions to produce a function having zeros in addition to all the qualitative properties of the original function. The calculation of the exact zeros of a function is often difficult and often must be accomplished by numerical methods on a computer. Zeros of many functions are tabulated in standard references such as Abramowitz and Stegun. 3 1.4.10. Integrability The function y = [(x) defined over the interval [a, b] has the integral

The integral exists if I converges to a single, bounded value for a given interval, and the function is then said to be integrable. Note that the integral I may exist under two abnormal circumstances: 1. Either a or b, or both, extend to infinity. 2. The function y has an infinite discontinuity at one or both endpoints or at one or more points interior to [a, b].

12

CRC Standard Curves and Surfaces

Under either of these circumstances, the integral is an improper integral. Proving the existence of the integral of a given function is not always straightforward, and a discussion is beyond the scope of this volume. Transient functions always have an integral on the interval [0,00] and are often given as solutions to physical problems in which the response of a medium to a given input or disturbance is sought. Such responses must possess an integral if the input was finite and measurable. Examples of such functions are y = e- ax sin(bx) and y = 1/(1 + x 2 ). Surfaces given by z = f(x, y) are integrable when

exists. Improper integrals of surfaces are defined in the same manner as those of two-dimensional curves. Transient responses exist for three dimensions and are integrable also. A curve property which has an important consequence for integration is that of even and odd functions. Even functions have f(x) = f( -x), and for such curves I=2[f(x)dx

o

if I exists over [-a, a]. For odd functions f(x) = f( -x), and 1= 0 over any interval [ - a, a]. This concept can be easily extended to surfaces. 1.4.11. Multiple Values A curve is multivalued if, for a given (x, y), it has two or more distinct values. A simple example is y2 = x. Multivalued functions are not integrable in the normal sense, although one or more particular branches of the curve may have well-defined integrals. While a curve may be multivalued in its Cartesian-form equation, the polar form of the equation may be single-valued, in the sense that only one value of r exists for each value of angle 8. Compare, for example,

which is the equation of a quadrifolium, with its polar equation r

=

cos(28)

Integrability is affected by the choice of coordinate system; this example shows that, when an integral is not defined due to a function being multivalued, it may be well defined when the transformation to polar coordinates is made and the integral evaluated along the polar angle 8.

13

Similarly, surfaces may be single valued or multivalued depending upon whether z takes on one or more values for a given (x, y) point. 1.4.12. Curvature Given that a differential of length along the curve path is ds and that the tangent line changes its direction over ds by an angle de, where e is the angle of the tangent with the x axis, then the radius of curvature is given by

p

=1 ~~ 1

This radius can be expressed in terms of the derivatives of the curve also. If the curve is expressed implicitly as f(x, y) = 0, and if fx and fy are the first partial derivatives and fxx, f yy , and fxy are the second partial derivatives, then

When the curve is expressed in polar coordinates and the derivatives dr I de and d 2r Ide 2 are given by r' and r" respectively, then the radius of curvature is 2

p

=

2 3/2

(r + r' ) r2 + 2r ,2 - rr"

~----~~--

The radius of curvature at lobes of polar curves is of interest in order to define the "tightness" of the lobes. At the peak of the lobe, r' = 0 and p = r 2/(r - r"), This reduces to p = r in the case of a circle, for which r" = O. Using the same formula as for curves above, the curvature of surfaces can be measured along any arbitrary linear arc of the surface made by an intersecting plane, where e is the angle of the tangent line relative to the horizontal in the intersecting plane. Thus the curvature of a surface is relative to the perspective it is viewed from.

1.5. CLASSIFICATION OF CURVES AND SURFACES The family of two-dimensional and three-dimensional curves can be displayed as in Figure 6. This schematic reflects the organization of this reference work, and every curve which can be traced by a given mathematical equation or given set of mathematical rules can be placed in one of the categories shown. There is a top-level dichotomy between determinate and random curves; but, except for Chapter 14, no further reference will be made

14

CRC Standard Curves and Surfaces

ALGEBRAIC

mulNAL) NON-GAUSSIAN

RATIONAL

POLYNL

LOGARTIHMIC

~OLYNOMIAL

TIUGONOMETIU~~GO~ REGULAR IRREGULAR FRAcrAL

FIGURE 6. A classification of curves and surfaces for this handbook.

to random curves in this volume. A determinate curve is one for which the functional relationship between x and y is known everywhere from the equation or set of rules in the abstract. No realization is required to produce the curve, for it is contained wholly within its defining equations or rules. On the other hand, a random curve will have a random factor or term in its mathematical definition such that an actual realization is required to produce the curve, which will differ from any other realization. For example, y = sin(x) + w(x), where w(x) is a random variable on x, defines a random curve. At the second level in Figure 6, the distinction is made between algebraic, transcendental, integral, and piecewise continuous curves as described below. 1.5.1. Algebraic Curves A polynomial is defined as a summation of terms composed of integral powers of x and y. An algebraic curve is one whose implicit function

f(x,y)=O is a polynomial in x and y (after rationalization, if necessary). Because a curve is often defined in the explicit form y

=

f(x)

there is a need to distinguish rational and irrational functions of x. A rational function of x is a quotient of two polynomials in x, both having only integer powers. An irrational function of x is a quotient of two polynomials, one or both of which has a term (or terms) with power p/q, where p and q

are integers. Irrational functions can be rationalized, but the curves will not be identical before and after rationalization. In general, the rationalized form has more branches; for example, consider y = x 1/2, which is rationalized to y 2 = x. The former curve has only one branch (for positive y) if a strict

15

definition of the radical is used, whereas the latter has two branches, for y < 0 and y > O. In this book, the rationalized curve will be presented

graphically in all cases, even though the equation is printed in its irrational form for simplicity. Besides simple polynomials, rational functions are often grouped into sets convenient for certain mathematical applications. Examples of such polynomial sets are Chebyshev polynomials, Laguerre polynomials, and Bernoulli polynomials. Many polynomial sets have the property of orthogonality, meaning that for any two functions II and 12 of the set,

over the defined domain of x for that set, where w(x) is a weighting function. This property ensures that the different curves within the set make distinct contributions to the set. 1.5.2. Transcendental Curves The transcendental curves cannot be expressed as polynomials in x and y. These are curves containing one or more of the following forms: exponential (eX), logarithmic (log x), or trigonometric (sin x, cos x). (The hyperbolic functions are often mentioned as part of this group, but they are not really distinct because they are forms composed of exponential functions.) Any curve expressed as a mixture of transcendentals and polynomials is considered to be transcendental. All of the primary transcendental functions can, in fact, be expressed as infinite polynomial series: n

00

eX =

L n~O

-x

(-oo<x for spherical coordinates in three dimensions. 1.6.6. Radial Translation In two dimensions, if the radial coordinate is translated according to

r' = r + a

19

then the entire curve moves outward by the amount a from the origin. Note that this operation is not homomorphic like Cartesian translation, because the curve is stretched in the angular direction while undergoing the radial translation. This operation can be performed on the radial coordinate of either cylindrical or spherical coordinate systems in three dimensions. 1.6.7. Weighting In a two-dimensional Cartesian system, let

This operation weights the curve by the factor Ixl a , a symmetric operator. If a > 0, the curve is stretched in the y direction by a factor which increases with x; but if a < 0, the curve is compressed by a factor which decreases with x. Similar treatments can be performed on surfaces in three dimensions. 1.6.8. Nonlinear Scaling If in two dimensions the scaling

is performed, the curve is progressively scaled upward or downward in absolute value, according to whether a > 1 or a < 1. Note that if y < and a = 2,4, 6, ... , then the scaled curve will flip to the opposite side of the x axis. Similar scalings can be made in three dimensions using any of the appropriate coordinate systems.

°

1.6.9. Shear A curve undergoes simple shear when either all its x coordinates or all its y coordinates remain constant while the other set is increased in proportion to x or y, respectively. The general transformations for simple shearing of a two-dimensional curve are x' = x

+ ay

y' = bx

+y

The transformations for simple x shear are x' = x

y' =y

+ ay

20

CRC Standard Curves and Surfaces

and for simple y shear are

x' =x y' ~ y

+ bx

Surfaces may be simply sheared along one or two axes with similar transformations. Another special case of shear is termed pure shear; the transformations for a two-dimensional curve are given by x'

=

Joe

For surfaces, pure shear will only apply to two of the three coordinate directions, with the remaining one having no change. Pure shear is a special case of linear scaling under this circumstance. 1.6.10. Matrix Method for Transformation The foregoing transformations can all be expressed in matrix form, which is often convenient for computer algorithms. This is especially true when several transformations are concatenated together, for the matrices can then be simply multiplied together to obtain a single transformation matrix. Given a pair of coordinates (x, y), a matrix transformation to obtain the new coordinates (x', y') is written as ( x'

y')

= (

Y) (~

x

~)

or explicitly x' = ax

+ cy

y' = bx

+ dy

According to this definition, Table 1 lists several of the x-y transformations discussed previously with their corresponding matrix. Translations cannot be treated with the above matrix definition. An extension is required to produce what is commonly referred to as the homogeneous coordinate representation in computer graphics programming. In its simplest form, an additional coordinate of unity is appended to the pair (x, y) to give (x, y, 1). A translation by u and v in the x and y directions is then written using a 3-by-3 matrix

(x'

o y'

l)=(x

y

1 v

~)

21

where, explicitly,

=x

+u

y' = y

+v

X'

l' = 1

With this representation, a radial translation by s units of a curve given in Cr, (J) coordinates is effected by

( r' so that r' = r

1) = (r

(J'

+ sand

(J

o (J

1

o

is unchanged. Table 1

Operation

Matrix

0

Rotation

(

Linear scaling

(~ ~)

Reflection

(~1 :1)

Weighting

(~

Nonlinear scaling Simple shear Rotational scaling

cos -sinO

sin cos

Notes

0) 0

o is counterclockwise angle from positive x axis.

Use + or - according to whether reflection is about x axis, y axis, or origin.

xOa )

(~ yOa)

Un (~

n

Use with (r, 0) coordinates.

1.7. METHOD OF PRESENTATION This reference work is basically intended to be illustrative; therefore all functions, whether curves or surfaces, will have an accompanying plot showing the form of the function. The plot will in all cases be on the right-hand page, while the equation will be on the facing left-hand page. Curves and surfaces and their plots are numbered for easy reference and grouped according to type. Wherever popular names exist for certain curves or surfaces, they are placed with the equations themselves.

22

CRC Standard Curves and Surfaces

1.7.1. Equations The equation of each algebraic or transcendental curve will be given in the explicit form y = f(x) or r = fee) wherever possible; similarly, surfaces will be given as z = f(x, y) or r = fee, z) or r = fee, 1, while still letting x vary between -1 and + 1. Similarly, the range of y can be limited to ± 1 by plotting y = c . f(x), where the constant c is suitably chosen. Three-dimensional curves and surfaces will have the additional z axis, also from -1 to + 1, and will be plotted in a projection which satisfactorily illustrates the form of each function. Simple equations will be illustrated by a single plotted curve or surface, while more complicated equations may have two or more such plots with different constants in order to indicate the variation possible in a family of curves or surfaces. In the case of curves which are unbounded in y (for example, y = 1/x), the evaluation algorithm computes and plots the curve at exactly y = + 1 or y = -1. Curves expressed in polar coordinates (r, e) are similarly truncated at r = 1 in the case that r is unbounded. The implicit form of a curve will often comprise more points than a corresponding explicit form. For example, y 2 - X = 0 has two ranges in y, one positive and one negative, while the

23

explicit form derived from solving the above equation gives y = xl/2, for which the range of y is positive only; in such cases both the positive and the negative range of yare plotted.

REFERENCES 1. Buck, R. c., Advanced Calculus, McGraw-Hill, New York, 1965, Chap. 5. 2. Poston, T., and I. Stewart, Catastrophe Theory and Its Applications, Pitman, New York, 1978. 3. Abramowitz, M., and I. A. Stegun, Eds., Handbook of Mathematical Functions, National Bureau of Standards, Department of Commerce, Washington, D.C., 1964. 4. Mandelbrot, B. B., The Fractal Geometry of Nature, W. H. Freeman, San Francisco, 1983. 5. Hayes, B., Computer recreations: Turning turtle gives one a view of geometry from the inside out, Sci. Am., 250, 14, 1984.

25

Chapter 2

ALGEBRAIC CURVES The curves of this chapter are mostly familiar equations found in tables of integrals. Many have acquired traditional or accepted names in the mathematical literature, and these are included wherever appropriate. The last section deals with curves more readily expressed in polar coordinates; this allows much easier computation of the curves than with the form y = I(x), especially when curves are multivalued in that form. For curves involving radicals, both the positive and negative branches are plotted to show the symmetry.

26

CRC Standard Curves and Surfaces

2.1. FUNCTIONS WITH x n / 2.1.1. y = cx n

1. 2. 3. 4. 5. 6.

c = c = c = c = c = c =

1, 1, 1, 1, 1, 1,

n

n n

n n n

y - cx n = 0 1 (linear) = 3 (cubic) = 5 (quintic) = 2 (quadratic, or simple parabola) = 4 (quartic) = 6 (sextic) =

= c/x n c = 0.01, n = c = 0.01, n = c = 0.01, n = c = 0.01, n = c = 0.01, n = c = 0.01, n =

yxn -

2.1.2. y

1. 2. 3. 4. 5. 6.

1 (hyperbola) 3 5 2 4 6

C

= 0

m

27

2.1.1

2.1.1

2.1.2

2.1.2

28

CRC Standard Curves and Surfaces

2.1.3. y = cx n / m y - cx n / m = 0 1. c = 1, n = 1, m = 4 2. c = 1, n = 1, m = 2 3. c = 1, n = 3, m = 4 4. c = 1, n = 5, m = 4 5. c = 1, n = 3, m = 2 (semicubical parabola) 6. c = 1, n = 7, m = 4 7. c = 1, n = 1, m = 3 8. c = 1, n = 2, m = 3 (cusp catastrophe) 9. c = 1, n = 4, m = 3 10. c = 1, n = 5, m = 3 2.1.4. y = c/x n / m 1. c = 0.01, n = 1, m = 4 2. c = 0.01, n = 1, m = 2 3. c = 0.01, n = 3, m = 4 4. c = 0.01, n = 5, m = 4 5. c = 0.01, n = 3, m = 2 6. c = 0.01, n = 7, m = 4 7. c = 0.01, n = 1, m = 3 8. c = 0.01, n = 2, m = 3 9. c = 0.01, n = 4, m = 3 10. c = 0.01, n = 5, m = 3

yx n / m - c

= 0

29

2.1.3

2.1.3

2.1.4

2.1.4

CRC Standard Curves and Surfaces

30

2.2. FUNCTIONS WITH xn AND (a 2.2.1. y = e(a + bx) 1. a = 0.5, b = 0.5, e = 1.0 2. a = 0.5, b = 1.0, e = 1.0 3. a = 0.5, b = 2.0, e = 1.0

y - bex - ae

+ bx)m

= 0

2.2.2. y = e(a + bX)2 1. a = 0.5, b = 0.5, e = 1.0 2. a = 0.5, b = 1.0, e = 1.0 3. a = 0.5, b = 2.0, e = 1.0 2.2.3. y = e(a

+ bX)3

y - b 3ex 3

-a 3e = 1. 2.

3.

a a a

3ab 2ex 2 - 3a 2bex

-

0

= 0.5, b = 0.5, e = 1.0 = 0.5, b = 1.0, e = 1.0 = 0.5, b = 2.0, e = 1.0

2.2.4. y = ex(a + bx) 1. a = 0.5, b = 0.5, e = 1.0 2. a = 0.5, b = 1.0, e = 1.0 3. a = 0.5, b = 2.0, e = 1.0

y - bcx 2 - aex

= 0

2.2.5. y = cx(a + bx)2 1. a = 0.5, b = 0.5, e = 1.0 2. a = 0.5, b = 1.0, e = 1.0 3. a = 0.5, b = 2.0, e = 1.0 2.2.6. y = cx(a 1. 2. 3.

a a a

+ bx)3

= 0.5, b = 0.5, e = 1.0 = 0.5, b = 1.0, e = 1.0 = 0.5, b = 2.0, e = 1.0

- 3ab 2cx 3 -a 3 ex = 0

y - b 3cx 4

-

3a 2bcx 2

31 3

3

2

2

2.2.2

2.2.1 3

2

3

3

2

2

3

2.2.3

2.2.4 2 3

3

2

2

3

2.2.5

2.2.6

2

32

CRC Standard Curves and Surfaces

2.2.7. 1. 2. 3.

Y = cx 2(a + bx) a = 0.5, b = 0.5, c = 1.0 a = 0.5, b = 1.0, c = 1.0 a = 0.5, b = 2.0, C = 1.0

2.2.8. 1. 2. 3.

cx 2(a + bX)2 a = 0.5, b = 0.5, c = 1.0 a = 0.5, b = 1.0, c = 1.0 a = 0.5, b = 2.0, c = 1.0 Y

=

2.2.9. Y

=

cx 2(a

y - bcx 3

y - b 3cX 5

+ bx?

acx 2

-

-

-a 3 cx 2 = 1. 2. 3.

=

0

3ab 2cx 4

-

3a 2bcx 3

-

3a 2bcx 4

0

a = 0.5, b = 0.5, c = 1.0 a = 0.5, b = 1.0, c = 1.0 a = 0.5, b = 2.0, C = 1.0

2.2.10. Y = cx 3(a + bx) 1. a = 0.5, b = 0.5, C = 1.0 2. a = 0.5, b = 1.0, C = 1.0 3. a = 0.5, b = 2.0, C = 1.0

y - bcx 4

acx 3 = 0

-

2.2.11. Y = cx 3(a + bX)2 1. a = 0.5, b = 0.5, C = 1.0 2. a = 0.5, b = 1.0, C = 1.0 3. a = 0.5, b = 2.0, C = 1.0 2.2.12. y = cx3(a 1. 2. 3.

+ bX)3

a = 0.5, b = 0.5, a = 0.5, b = 1.0, a = 0.5, b = 2.0,

C

C C

y - b 3cX 6 -a 3cx 3

= 1.0 = 1.0 = 1.0

-

3ab 2cx 5

=

0

33 3

2

1 3

3

2

3

2.2.7

2.2.8 3

2

2

3

2.2.10

2.2.9 3

2

3

3

2

2

3

2.2.11

2.2.12

2

2 1

CRC Standard Curves and Surfaces

34

2.2.13. y = e/(a + bx) 1. a = 1.0, b = 2.0, e = 0.02 2. a = 1.0, b = 3.0, e = 0.02 3. a = 1.0, b = 4.0, e = 0.02

ay

+ bxy

- e

°

=

2.2.14. y = e/(a + bX)2 1. a = 1.0, b = 2.0, e = 0.02 2. a = 1.0, b = 3.0, e = 0.02 3. a = 1.0, b = 4.0, e = 0.02 2.2.15. y

=

e/(a

+ bX)3

a 3y

+ 2a 2bxy + 2ab 2x 2y + b 3x 3y

=0 1. 2.

3.

a = 1.0, b = 2.0, e = 0.02 a = 1.0, b = 3.0, e = 0.02 a = 1.0, b = 4.0, e = 0.02

2.2.16. y = ex/(a + bx) 1. a = 1.0, b = 2.0, e = 0.1 2. a = 1.0, b = 3.0, e = 0.1 3. a = 1.0, b = 4.0, e = 0.1

ay

+ bxy

- ex

=

°

2.2.17. y = ex/(a + bX)2 1. a = 1.0, b = 2.0, e = 0.02 2. a = 1.0, b = 3.0, e = 0.02 3. a = 1.0, b = 4.0, e = 0.02 2.2.18. y = ex/(a

1. 2.

3.

+ bX)3

a = 1.0, b = 2.0, e = 0.01 a = 1.0, b = 3.0, e = 0.01 a = 1.0, b = 4.0, e = 0.01

a 3y + 3a 2bxy -ex =

°

+ 3ab 2x 2y + b 3x 3 y

- e

35 23 1

23

23

2.2.13

2.2.14

1 23

2 3

2 3

1

23

2.2.15

2.2.16 2 3

1

1 1 2233

2.2.17

23

2.2.18

36

CRC Standard Curves and Surfaces

2.2.19. Y = ex 2/(a + bx) 1. a = 1.0, b = 2.0, e = 0.2 2. a = 1.0, b = 3.0, e = 0.2 3. a = 1.0, b = 4.0, e = 0.2

ay +bxy - ex 2

=

°

2.2.20. Y = ex 2/(a + bX)2 1. a = 1.0, b = 2.0, e = 0.1 2. a = 1.0, b = 3.0, e = 0.1 3. a = 1.0, b = 4.0, e = 0.1 a3 y

+ 3a 2bxy + 3ab 2x 2y + b 3 x 3 y

-ex 2 1.

2. 3.

°

=

a = 1.0, b = 2.0, e = 0.02 a = 1.0, b = 3.0, e = 0.02 a = 1.0, b = 4.0, e = 0.02

2.2.22. Y = ex 3 /(a + bx) 1. a = 1.0, b = 2.0, e = 1.0 2. a = 1.0, b = 3.0, e = 1.0 3. a = 1.0, b = 4.0, e = 1.0

+ bxy

ay

- ex 3 =

°

2.2.23. Y = ex 3 /(a + bx)2 1. a = 1.0, b = 2.0, e = 0.2 2. a = 1.0, b = 3.0, e = 0.2 3. a = 1.0, b = 4.0, e = 0.2 a3y

+ 3a 2bxy + 3ab 2x 2y + b 3 x 3 y

-ex 3 = 1. 2. 3.

a = 1.0, b = 2.0, e = 0.1 a = 1.0, b = 3.0, e = 0.1 a = 1.0, b = 4.0, e = 0.1

°

37 1

23

12233

2.2.20

2.2.19 1

23

1

2 3

1 23

2 3

2.2.22

2.2.21 2 3

-

-

7

I

1 23

12233

2.2.23

2.2.24

CRC Standard Curves and Surfaces

38

2.2.25. y = e(a + bx)lx 1. a = 1.0, b = 2.0, e = 0.04 2. a = 1.0, b = 4.0, e = 0.04 3. a = 1.0, b = 6.0, e = 0.04

xy - bex - ea

=

°

2.2.26. y = e(a + bxY Ix 1. a = 1.0, b = 2.0, e = 0.04 2. a = 1.0, b = 4.0, e = 0.04 3. a = 1.0, b = 6.0, e = 0.04 2.2.27. y = e(a

+ bX)3 Ix

xy - b 3cx 3 - 3ab 2cx 2 - 3a 2bcx - a 3e

=0 1. 2.

3.

a = 1.0, b = 2.0, e = 0.02 a = 1.0, b = 4.0, e = 0.02 a = 1.0, b = 6.0, e = 0.02

2.2.28. y = e(a + bx)lx 2 1. a = 1.0, b = 2.0, e = 0.04 2. a = 1.0, b = 4.0, e = 0.04 3. a = 1.0, b = 6.0, e = 0.04

x 2y - bex - ea =

°

2.2.29. y = e(a + bX)21x 2 1. a = 1.0, b = 2.0, e = 0.01 2. a = 1.0, b = 4.0, e = 0.01 3. a = 1.0, b = 6.0, e = 0.01 2.2.30. y = e(a

+

bX)31x 2

x 2y - b 3cx 3 - 3ab 2cx 2 - 3a 2bex

-a 3e 1. 2.

3.

a a a

= 1.0, b = 2.0, e = 0.003 = 1.0, b = 4.0, e = 0.003 = 1.0, b = 6.0, e = 0.003

=

°

39

- 3

3_ 2_

- 2 1

1~~_

~~_

2

3

2.2.25

2.2.26 3

3

2

~:

1

2 3

2.2.27

2.2.28

~:.

,

----=

~==:::::::::::::~_

1

~,

1--====---",~2

3

2.2.29

2.2.30

CRe Standard Curves and Surfaces

40

2.2.31. y = c(a + bx)jx 3 1. a = 1.0, b = 2.0, c = 0.02 2. a = 1.0, b = 4.0, c = 0.02 3. a = 1.0, b = 6.0, c = 0.02 2.2.32. y = c(a + bx )2jx 3 1. a = 1.0, b = 2.0, c = 0.01 2. a = 1.0, b = 4.0, c = 0.01 3. a = 1.0, b = 6.0, c = 0.01 2.2.33. y

= c(a + bX)3jx 3

x 3y - b 3cX 3 - 3ab 2cx 2 - 3a 2bcx

-a 3c = 1.

2. 3.

a a a

= 1.0, b = 2.0, c = 0.002 = 1.0, b = 4.0, c = 0.002 = 1.0, b = 6.0, c = 0.002

a

41

~,

2

2.2.31

2.2.32

3

1===--=

2

2.2.33

CRC Standard Curves and Surfaces

42

2.3. FUNCTIONS WITH a 2 2.3.1. Y = cj(a 2 + x 2 ) Special case: c = a 3 gives witch

1. 2.

3.

a a a

= 0.2, c = 0.04

= 0.5, c = 0.04 = 0.8, c = 0.04

2.3.2. y = exj(a 2 Serpentine

1. 2. 3.

a a a

+ x 2)

= 0.2, c = 0.3 = 0.5, c = 0.3 = 0.8, c = 0.3

2.3.3. y = ex 2 j(a 2 + x 2 ) 1. a = 0.2, c = 1.0 2. a = 0.5, c = 1.0 3. a = 0.8, c = 1.0 2.3.4. y = ex 3 j(a 2 + x 2 ) 1. a = 0.2, c = 1.0 2. a = 0.5, c = 1.0 3. a = 0.8, c = 1.0

+ x 2 AND

a2 y + x 2y of Agnesi

C

= 0

xm

43

1

~----~

2 3

2.3.1

2.3.2

2 3

2.3.3

2.3.4

44

CRC Standard Curves and Surfaces

2.3.5. y = c j[x(a 2 + x 2 )] 1. a = 0.2, c = 0.02 2. a = 0.5, c = 0.02 3. a = 0.8, c = 0.02 2.3.6. y = cj[x 2 (a 2 + x 2 )] 1. a = 0.2, c = 0.02 2. a = 0.5, c = 0.02 3. a = 0.8, c = 0.02 2.3.7. y = cx(a 2 + x 2 ) 1. a = 0.2, c = 1.0 2. a = 0.5, c = 1.0 3. a = 0.8, c = 1.0 2.3.8. y = cx 2 (a 2 + x 2 ) 1. a = 0.2, c = 1.0 2. a = 0.5, c = 1.0 3. a = 0.8, c = 1.0

4S 32

32 1

1

2.3.5

2.3.6 3

2.3.7

21

2.3.8

CRC Standard Curves and Surfaces

46

2.4. FUNCTIONS WITH a 2 2.4.1. Y = c/(a 2 1. a = 0.2, c = 2. a = 0.5, c = 3. a = 0.8, c = 2.4.2. 1. 2. 3.

x 2) 0.03 0.03 0.03

Y = cx/(a 2 - x 2 ) a = 0.2, c = 0.1 a = 0.5, c = 0.1 a = 0.8, c = 0.1

2.4.3. Y = cx 2 /(a 2

1. 2. 3.

a a a

- x 2) = 0.2, c = 0.2 = 0.5, c = 0.2

= 0.8, c = 0.2

2.4.4. Y = cx 3 /(a 2

1. 2. 3.

- x 2) = 0.2, c = 0.2 = 0.5, c = 0.2 a = 0.8, c = 0.2

a a

-

x 2 AND xm

47 1

2

3

1

2

3

( 1

2.4.1

2

3

1

", 0

2

3

2.4.2

"!

~-

\\\(7( 1

2.4.3

2

3

1

2.4.4

((

2

3

48

CRC Standard Curves and Surfaces

2.4.5. 1. 2. 3.

Y = c/[x(a 2 - x 2 )] a = 0.2, c = 0.001 a = 0.5, c = 0.001 a = 0.8, c = 0.001

2.4.6. 1. 2. 3.

Y= a = a = a =

2.4.7. Y = 1. a = 2. a = 3. a = 2.4.8. 1. 2. 3.

c/[x 2 (a 2

-

x 2 )]

0.2, c = 0.0003 0.5, c = 0.0003 0.8, c = 0.0003 cx(a 2

-

x 2)

0.2, c = 1.0 0.5, c = 1.0 0.8, c = 1.0

Y = cx 2 (a 2 a = 0.2, c = a = 0.5, c = a = 0.8, c =

x2)

4.0 4.0 4.0

49 2

1

3

3

VV

U J

2

~

"'I

~

(

123

123

2.4.6

2.4.5

3

2 12

2.4.7

2.4.8

3

CRC Standard Curves and Surfaces

50

2.5. FUNCTIONS WITH a 3 2.5.1. 1. 2. 3.

Y

=

ej(a 3 + x 3 ) a = 0.2, e = 0.01 a = 0.3, e = 0.01 a = 0.4, e = 0.01

2.5.2. 1. 2. 3.

Y

=

2.5.3. 1. 2. 3. 2.5.4. 1. 2. 3.

a

=

a

=

a

=

exj(a 3 + x 3 ) 0.1, e = 0.01 0.3, e = 0.01 0.5, e = 0.01

Y = ex 2 j(a 3 + x 3 ) a = 0.1, e = 0.1

a

=

a

=

0.3, e 0.5, e

= =

0.1 0.1

Y = ex 3 j(a 3 + x 3 ) a = 0.1, e = 0.2

a a

= =

0.3, e 0.5, e

= =

0.2 0.2

2.5.5. 1. 2. 3.

Y = ej[x(a 3 + x 3 )] a = 0.5, e = 0.01

2.5.6. 1. 2. 3.

Y = ex(a 3 + x 3 ) a = 0.5, e = 1.0 a = 0.7, e = 1.0 a = 0.9, e = 1.0

a = 0.7, e = 0.01 a = 0.9, e = 0.01

+ x 3 AND

xm

51 3

3 2

2

3 21

2.5.1

2.5.2 3

2

J 3

2.5.3 3

3

2.5.4

2

2

3 21

n 1

2.5.5

2.5.6

52

CRC Standard Curves and Surfaces

2.6. FUNCTIONS WITH a 3 2.6.1. 1. 2. 3. 2.6.2. 1. 2. 3.

Y = e/(a 3 = 0.2, e = a = 0.3, e = a = 0.4, e = a

x 3) 0.01 0.01 0.01

Y = ex/(a 3 - x 3 ) = 0.1, e = 0.01 = 0.3, e = 0.01 = 0.5, e = 0.01

a a a

2.6.3. y = ex 2 /(a 3 - x 3 ) 1. a = 0.1, e = 0.1 2. a = 0.3, e = 0.1 3. a = 0.5, e = 0.1

2.6.4. Y = ex 3 /(a 3 - x 3 ) 1. a = 0.1, e = 0.2 2. a = 0.3, e = 0.2 3. a = 0.5, e = 0.2 2.6.5. Y = e/[x(a 3 - x 3 )] 1. a = 0.5, e = 0.01 2. a = 0.7, e = 0.01 3. a = 0.9, e = 0.01 2.6.6. 1. 2. 3.

Y = ex(a 3 - x 3 ) a = 0.5, e = 1.0 a = 0.7, e = 1.0 a = 0.9, e = 1.0

-

x 3 AND xm

53 2

123

2.6.1

2.6.2

3

2.6.4

2.6.3

2

2.6.5

2

3

2.6.6

3

54

CRC Standard Curves and Surfaces

2.7. FUNCTIONS WITHa 4 2.7.1. Y = c/(a 4 + x 4 ) 1. a = 0.3, C = 0.007 2. a = 0.4, C = 0.007 3. a = 0.5, C = 0.007 Y = cx/(a 4 + x 4 ) = 0.2, C = 0.01 = 0.3, C = 0.01 = 0.4, C = 0.01

2.7.2. 1. 2. 3.

a a a

2.7.3. 1. 2. 3.

a = 0.3, c = 0.15 a = 0.4, c = 0.15 a = 0.5, c = 0.15

2.7.4. 1. 2. 3.

a a a

Y = cx 2 /(a 4

Y

+ x 4)

= cx 3 /(a 4 + x 4 ) = 0.2, c = 0.25 = 0.4, c = 0.25

= 0.6, c = 0.25

2.7.5. Y = cx 4 /(a 4 + x 4 ) 1. a = 0.2, c = 1.0 2. a = 0.5, c = 1.0 3. a = 0.8, c = 1.0 2.7.6. Y = cx(a 4 + x 4 ) 1. a = 0.5, c = 0.5 2. a = 1.0, c = 0.5 3. a = 1.2, c = 0.5

+ X4 AND xm

55

2.7.1

2.7.2

2.7.3

2.7.4 3

~---1 3

2.7.5

2.7.6

2

56

CRC Standard Curves and Surfaces

2.8. FUNCTIONS WITH a 4 2.8.1. Y = c/(a 4 - x 4 ) 1. a = 0.4, C = 0.01 2. a = 0.6, C = 0.01 3. a = 0.8, C = 0.01 2.8.2. Y = cx/(a 4 - x 4 ) 1. a = 0.2, c = 0.01 2. a = 0.4, c = 0.01 3. a = 0.6, c = 0.01 2.8.3. y = ex 2/(a 4 - x 4) 1. a = 0.2, c = 0.1 2. a = 0.4, c = 0.1 3. a = 0.6, c = 0.1 2.8.4. y = cx 3 /(a 4 - x 4 ) 1. a = 0.2, c = 0.1 2. a = 0.4, c = 0.1 3. a = 0.6, c = 0.1 2.8.5. y = cx 4 /(a 4 - x 4 ) 1. a = 0.2, c = 0.1 2. a = 0.5, c = 0.1 3. a = 0.8, c = 0.1 2.8.6. y = cx(a 4 - x 4 ) 1. a = 0.4, c = 1.0 2. a = 0.8, c = 1.0 3. a = 1.0, c = 1.0

-

X4

AND xm

57 2

3

2

3

2.8.1

2

2.8.2 2

3

2

2.8.3

2.8.4 2

2

2.8.5

3

3

3

2.8.6

3

58

CRC Standard Curves and Surfaces

2.9. FUNCTIONS WITH (a 2.9.1. y = c(a

+ bX)lj2 AND

xm

+ bx)1/2

Parabola 1. 2. 3.

a a a

= 0.5, b = 0.5, c = 1.0 = 0.5, b = 1.0, c = 1.0

= 0.5, b = 2.0, c

2.9.2. y = cx(a

=

1.0

+ bX)1/2

Special case: c = 1/(3a) and b = "trisectrix of Catalan") 1. 2. 3.

a = 0.5, b = 0.5, c = 1.0 a = 0.5, b = 1.0, c = 1.0 a = 0.5, b = 2.0, c = 1.0

+ bx)1/2

2.9.3. 1. 2. 3.

y = cx 2(a a = 0.5, b a = 0.5, b a = 0.5, b

2.9.4. 1. 2. 3.

y a a a

2.9.5. 1. 2. 3.

= c(a + bX)1/2/X2 a = 0.5, b = 0.5, c = 0.1 a = 0.5, b = 1.0, c = 0.1 a = 0.5, b = 2.0, c = 0.1

2.9.6. 1. 2. 3.

y = c/(a + bX)1/2 a = 1.0, b = 1.0, c a = 1.0, b = 2.0, c a = 1.0, b = 4.0, c

= 0.5, c = 1.0 = 1.0, c = 1.0 = 2.0, c = 1.0

= c(a + bx)1/2/ X = 0.5, b = 0.5, c = 0.2 = 0.5, b = 1.0, c = 0.2 = 0.5, b = 2.0, c = 0.2

y

= 0.5 = 0.5 = 0.5

y2 - bC 2X 3 - ac 2x 2 = 0 1 gives Tschimhauser's cubic (also called

59

2.9.1

2.9.2

2.9.3

2.9.4

2.9.5

2.9.6

60

CRC Standard Curves and Surfaces

2.9.7. 1. 2. 3.

y = cx/(a + bX)1/2 a = 1.0, b = 1.0, c = 1.0

2.9.8. 1. 2. 3.

y = cx 2/(a + bX)1/2 a = 1.0, b = 1.0, c = 1.0

a = 1.0, b = 2.0, c = 1.0 a = 1.0, b = 4.0, c = 1.0

a = 1.0, b = 2.0, c = 1.0 a = 1.0, b = 4.0, c = 1.0

2.9.9. y = c/[x(a + bX)1/2] 1. a = 1.0, b = 0.8, c = 0.2 2. a = 1.0, b = 1.0, c = 0.2 3. a = 1.0, b = 1.2, c = 0.2 2.9.10. y = c/[x 2(a + bX)1/2] 1. a = 1.0, b = 0.8, c = 0.1 2. a = 1.0, b = 1.0, c = 0.1 3. a = 1.0, b = 1.2, c = 0.1 2.9.11. y = cx 1/ 2(a + bX)1/2 1. a = 2.0, b = - 2.0, c = 1.0 2. a = 2.0, b = - 3.0, c = 1.0 3. a = 2.0, b = - 4.0, c = 1.0 4. a = 0.3, b = 1.0, c = 1.0 5. a = 0.5, b = 1.0, c = 1.0 6. a = 0.7, b = 1.0, c = 1.0

61

2 3

2

2

3

2.9.7

2.9.8

'((\

'7(\ 2

3

2

3

2.9.9

3

2.9.10 654

6 5 4

2.9.11

2.9.11

62

CRC Standard Curves and Surfaces

2.9.12. Y = cx 3/ 2(a Special case: b
2, hypoellipse for n/m < 2 1. 2. 3. 4.

5. 6.

0.5, 0.5, 0.5, 0.5, 0.5, 0.5,

y = = = a = a = a =

= e(1 + Ix/aln/m)m/n

2.13.11. 1. a 2. a 3. a 4.

5. 6.

0.2, 0.2, 0.2, 0.2, 0.2, 0.2,

n/m = n /m = n/m = n/m = n/m = n/m =

i, e =

a = a= a = a = a = a =

n/m n/m n/m n/m n/m n/m

= = = = = =

1.0

j, e = 1.0 1, 1, 2, 4,

e e e e

= = = =

1.0 1.0 1.0 1.0

i, e = 0.2

j, e = 0.2

1, 1, 2, 4,

e e e e

= = = =

0.2 0.2 0.2 0.2

yn/m _ elx/al n / m - e = 0

83 3

2.13.9

2.13.10

2.13.10 2

2.13.11

4

3

2.13.11

56

84

CRC Standard Curves and Surfaces

2.13.12. y

=

cx axn

= 10.0, 2. a = 10.0, 3. a = 10.0, 4. a = 2.0, 5. a = 5.0, 6. a = 8.0, 1.

a

c c c c c c

= = = = = =

1.0, 1.0, 1.0, 1.0, 1.0, 1.0,

n n

n

a = 0.75, c = 5.0 a = 1.00, c = 5.0 a = 1.50, c = 5.0

2.13.14. y = cx(1 + a 2x 2)2 1. a = 1.0, c = 0.1 2. a = 2.0, c = 0.1

3.

a

=

4.0, c

=

0.1

= 3

n = 2 n = 2

2.13.13. y = c(1 - x2)a/x

1. 2. 3.

= 1

n = 2

= 2

85

2.13.12

2.13.12

2.13.13

2.13.14

CRC Standard Curves and Surfaces

86

2.13.15. 1. a 2. a 3. a

cx 2(1 = 1.0, c = = 2.0, c = = 4.0, c = y

=

2.13.16. xn -

n-roll mill 1. 2.

n = 2 n = 3

+ a 2x 2)2 0.1 0.1 0.1

(~)xn-2y2 + (~)xn-4y4 - ...

=

an

87

2.13.15 2

00 2.13.16

II 2.13.16

CRC Standard Curves and Surfaces

88

2.14. ALGEBRAIC FUNCTIONS EXPRESSIBLE IN POLAR COORDINATES 2.14.1. r = c(2a cos 8 + 1) Limaq,on of Pascal Domain: [0 < 8 < 21T] Special cases: a = ~ gives cardioid a = 1 gives trisectrix 1. 2. 3.

a a a

= 1.00, c = 0.25 = 0.50, c = 0.50 = 0.25, c = 0.50

2.14.2. r2 = c 2 cos 28 Lemniscate of Bernoulli Domain: [0 < 8 < 21T] 1.

c

=

1.0

2.14.3. r = c cot 8 Kappa curve Domain: [0 < 8 < 21T] 1.

c

=

0.6

2.14.4. r2 = c 2(1 - a 2 sin 2 8) Hippopede curve Domain: [0 < 8 < 21T] 1. 2.

3.

a a a

= 0.70, c = 1.0 = 0.85, c = 1.0 = 1.00, c = 1.0

89

2.14.1

2.14.2

2.14.3

2.14.4

90

CRC Standard Curves and Surfaces

2.14.5.

r2

= a

2

. 2

8

b2

cos sin 2 8 - cos 2 8

SIll

-

2

8

Devil's curve Domain: [0 < 8 < 27T] 1. 2.

3.

a = 0.2, b = 0.8 = 0.4, b = 0.8 = 0.6, b = 0.8

a a

2.14.6. r = (cos 8)(4a sin 2 8 - b) Folium Domain: [0 < 8 < 7T] 1. 2. 3.

a a a

= 0.25, b = 1.0

= 0.50, b = 1.0 = 1.00, b = 1.0

2.14.7. r = c sin 8 cos 2 8 Bifolia Domain: [0 < 8 < 7T] 1. 2.14.8.

c = 3.0 r2

= (b 4

a 4 sin 2 28)1/ 2 +a 2 COS 28 -

(x 2

+ y2 + a 2 )2

Cassinian oval Special case: a = b gives lemniscate of Bernoulli Domain: [0 < 8 < 27T] 1. 2. 3.

a = 0.45, b = 0.5 a = 0.50, b = 0.5 a = 0.55, b = 0.5

'-k

-

4a 2 x 2

-

b1 =

0

91 3 2 1

3

2.14.5

2.14.6

2.14.7

2.14.8

CRC Standard Curves and Surfaces

92 2.14.9.

r = c[1 + 2 sinCe /2)]

(x 2 + y2)(X 2 + y2 + e 2 - 2ef -[2e(x2 + y2) - 2ex] = 0

Nephroid of Freeth Domain: [0 1.

< e < 4'7T]

e = 0.3

2.14.10. r

= e cos 3 (e /3)

4(x 2 + y2 _ ex)3 _ 27e2(x2

=0 Cayley's sextet Domain: [0 1.

< e < 3'7T]

e = 1.0 1-acose

2.14.11. r

= e 1 + a cos e

Domain: [0 1.

2. 3. 4.

a a

< e < 2'7T]

= 0.50, e = 0.3 = 0.675, e = 0.3

a = 1.00, e = 0.3 a

= 10.0,

e = 0.3

+ y2 + ac.x:)Z -(x 2 + y2)(e -

(x 2

ax)2

= 0

+ y2)2

93

2.14.9

2.14.10

2.14.11

2.14.11

3

4

4

CRC Standard Curves and Surfaces

94

2.15. ALGEBRAIC FUNCTIONS EXPRESSED PARAMETRICALLY c(8at 3 + 24t 5 ) y = c( - 6at 2 - 15t 4 ) Butterfly catastrophe

2.15.1.

1. 2.

X =

a a

= -5.0, c = 0.03; -1.46 < t < 1.46 = -7.0, c = 0.02; -1.68 < t < 1.68

2.15.2. x = c( - 2at - 4t 3 ) y = c(at 2 + 3t 4 ) Swallowtail catastrophe

1. 2.

a a

= -1.0, c = 0.5; -1 < t < 1

= - 2.0, c = 0.5; - 2 < t < 2

95 2

2.15.1

2.15.1 2

2.15.2

2.15.2

97

Chapter 3

TRANSCENDENTAL FUNCTIONS This chapter treats the transcendental functions: trigonometric, logarithmic, and exponential. The equations found in this chapter can mostly be found in tables of integrals. Traditional or accepted names for certain curves are included wherever appropriate. A final section of the chapter comprises curves which are more easily expressed in the polar form r = fUJ) than in the Cartesian form y = f(x).

98

CRC Standard Curves and Surfaces

3.1. TRIGONOMETRIC FUNCTIONS WITH sinn(ax) AND cosm(bx) (n, m INTEGERS) 3.1.1. Y = sin(27Tx) 3.1.2. y = COS(27T x) 3.1.3. y = tan(27Tx) 3.1.4. y = COt(27TX) 3.1.5. y = 0.25 CSC(27TX) 3.1.6. Y = 0.25 sec(27Tx)

99

3.1.1

3.1.2

3.1.3

U U) ~ n n n n 3.1.5

3.1.6

100

CRC Standard Curves and Surfaces

3.1.9. y = sin(27Tax) sin(27Tbx) Modulated sine wave

1. 2. 3. 4.

a

=

a

=

0.5, 0.5, a = 0.5, a = 0.5,

b = 1.0 b = 1.5 b = 2.0 b = 2.5

3.1.10. y = cos(27Tax)cos(27Tbx) 1. a = 0.5, b = 1.0 2. a = 0.5, b = 1.5 3. a = 0.5, b = 2.0 4. a = 0.5, b = 2.5

101

3.1.7

3.1.8

3.1.9

3.1.9 2

3.1.10

3.1.10

102

CRC Standard Curves and Surfaces

3.1.11. y = sin(27Tax)cos(27Tbx) 1. a = 0.5, b = 1.0 2. a = 0.5, b = 1.5 3. a = 0.5, b = 2.0 4. a = 0.5, b = 2.5 3.1.12. Y = 2.0 sin(27Tx) cos 2 (27TX) 3.1.13. y

=

2.0 COS(27TX) sin 2 (27Tx)

103

3.1.11

3.1.11

3.1.12

3.1.13

104

CRC Standard Curves and Surfaces

3.1.14. Y

=

0.25 sin(27Tx)jcos 2 (27TX)

3.1.15. y = 0.25 sin 2 (27Tx)jcos(27TX) 3.1.16. y = 0.25 COS(27Tx)jsin 2 (27Tx) 3.1.17. y

=

0.25 cos 2 (27Tx)jsin(27Tx)

105

3.1.14

3.1.15

3.1.16

3.1.17

106

CRC Standard Curves and Surfaces

3.2. TRIGONOMETRIC FUNCTIONS WITH 1 ± sinn(ax) AND 1 3.2.1. y

=

0.5/[1 +

± cosm(bx)

COS(27T x)]

3.2.2. Y = 0.5/[1 - COS(27TX)]

+ COS(27TX)]

3.2.3. y

=

0.5[sin(27Tx)]j[1

3.2.4. Y

=

0.5[sin(27Tx)]j[1 - COS(27TX)]

3.2.5. Y

=

0.5[cos(27Tx)]/[1

+ COS(27TX)]

3.2.6. y = 0.5[cos(27Tx)]j[1 - COS(27TX)]

107

~

)

uu

3.2.1

3.2.2

3.2.3

3.2.4

3.2.5

3.2.6

108

CRC Standard Curves and Surfaces

3.2.7. Y = 0.5/[1 3.2.8. Y

=

3.2.9. Y = 1. a = 2. a = 3. a =

+ COS(27TX)]l/2

0.5/[1 - COS(27T x )]1/2 0.5/[a 2 + b 2 cos 2(27TX)] 0.0, b = 1.0 1.0, b = 1.0 2.0, b = 1.0

3.2.10. Y = 0.5/[a 2 - b 2 COS 2(27TX)] 1. a = 0.0, b = 1.0 2. a = 1.0, b = 1.0 3. a = 2.0, b = 1.0 3.2.11. Y = sin(27Tx)/[1

+ cos 2(27TX)]

109

)

~

3.2.9

3.2.11

uu

\ n n(' 3.2.10

3.2.12

110

CRe Standard Curves and Surfaces

3.2.13. y = 2.0[sin(2'7Tx)]j[1

+ sin 2 (2'7Tx)]

3.2.14. y = 2.0[cos(2'7Tx)]j[1

+ cos 2 (21TX)]

3.2.15. y = [sin 2(2'7Tx)]j[1

+ cos 2(2'7Tx)]

3.2.16. y = [cos2(2'7Tx)]j[1

+ sin 2(2'7Tx)]

3.2.17. y = 2.0[sin 2 (2'7Tx)]j[1

+ sin2(2'7Tx)]

3.2.18. y = 2.0[cos 2(2'7Tx)}j[1

+ cos 2(2'7Tx)]

111

3.2.13

3.2.14

3.2.15

3.2.16

3.2.17

3.2.18

112

CRC Standard Curves and Surfaces

3.3. TRIGONOMETRIC FUNCTIONS WITH a sinn(cx) + b cosm(cx) 3.3.1. 1. 2. 3.

a COS(27TX) + b sin(27Tx) 0.4, b = 0.8 a = 0.6, b = 0.6 a = 0.8, b = 0.4

3.3.2. 1. 2. 3.

Y = l/[a COS(27TX) + b sin(27Tx)] a = 1.0, b = 1.0 a = 1.0, b = 2.0 a = 1.0, b = 4.0

3.3.3. 1. 2. 3.

Y = a 2 COS 2 (27TX) a = 0.25, b = 1.0 a = 0.50, b = 1.0 a = 0.75, b = 1.0

Y a

3.3.4. Y 1. a 2. a 3. a 3.3.5. 1. 2. 3.

=

=

= = = =

+ b 2 sin2 (27Tx)

1/[a 2 cos 2 (27TX) 1.0, b = 1.5 1.0, b = 2.0 1.0, b = 4.0

+ b 2 sin2 (27Tx)]

Y = [sin(27Tx)]j[a COS(27TX) + b sin(27Tx)] a = 1.0, b = 2.0 a = 1.0, b = 4.0 a = 1.0, b = 6.0

3.3.6. Y = 1. a = 2. a = 3. a =

[COS(27Tx)]j[a COS(27TX) 1.0, b = 2.0 1.0, b = 4.0 1.0, b = 6.0

+ b sin(27Tx)]

113 1 23

3 2

~ ~

1 23

3.3.1

3.3.2

3

3.3.4

3.3.3 123

123

3 1

3.3.5

3.3.6

114

CRC Standard Curves and Surfaces

3.4. TRIGONOMETRIC FUNCTIONS OF MORE COMPLICATED ARGUMENTS 3.4.1. y 1. a

=

3.4.2. y 1. a

=

=

=

sin(a1T Ix) 1.0

cos(a1T /x) 1.0

3.4.3. y = sin(a1Tlxl n1m ) 1. a = 4.0, n/m = t 2. a = 4.0, n/m = 2 3.4.4. y = cos(a1Tlxl n1m ) 1. a = 4.0, n/m = t 2. a = 4.0, n/m = 2

115

3A.1

3A.2 2

3A.3

3A.3 2

3AA

3AA

CRC Standard Curves and Surfaces

116

3.4.5. y = sin[ 7T cos(a7T x) /2] 1. a = 2.0 3.4.6. y = sin[ 7T sin(a7T x) /2] 1. a = 2.0 3.4.7. y = cos[7Tsin(a7Tx)/2] 1. a = 2.0 3.4.8. y = 1.

a

COS[7T

= 2.0

cos(a7Tx)/2]

117

3.4.5

3.4.6

3.4.7

3.4.8

118

CRC Standard Curves and Surfaces

3.5. INVERSE TRIGONOMETRIC FUNCTIONS 3.5.1. Y = (1/17 )arcsin x 3.5.2. y = (1/17 )arccos x 3.5.3. y = (l/17)arctan lOx 3.5.4. y = (1/17)arccot lOx 3.5.5. y = (1/17 )arcsec lOx 3.5.6. y = (1/17 )arccsc 10 x

119

3.5.1

3.5.2

3.5.3

3.5.4

3.5.5

3.5.6

CRC Standard Curves and Surfaces

120

3.6. LOGARITHMIC FUNCTIONS 3.6.1. y = 0.25 In lOx 3.6.2. y = 0.25 In[lj(lOx)] 3.6.3. y 3.6.4. y 1. 2.

3.

=

0.25 jln lOx

= 0.5 In[(x = 0.1 = 0.3 a = 0.5

a a

+ a)j(x

- a)]

121

3.6.1

3.6.2

3.6.3

3.6.4

CRC Standard Curves and Surfaces

122

3.6.5. 1. 2. 3.

y

=

a =

a

=

a

=

0.5In(x 2 0.5 1.0 2.0

+ a2)

3.6.6. Y = 0.25In[10(x 2 1. a = 0.1 2. a = 0.3 3. a = 0.5 3.6.7. y = 1. a = 2. a = 3. a =

O.5ln[x 0.1 0.3 0.5

3.6.8. y = O.5ln[x 1. a = 0.1 2. a = 0.3 3. a = 0.5

-

a 2 )]

+ (x 2 + a 2 )1/2]

+ (x 2 -

a 2 )1/2]

123

3

123

3

3.6.5

3.6.6

3.6.7

3.6.8

2

CRC Standard Curves and Surfaces

124

3.7. EXPONENTIAL FUNCTIONS 3.7.1. 1. 2. 3. 4.

5. 6.

y a a a a a a

= ce ax = = =

= = =

1.0, c = 0.1 2.0, c = 0.1 3.0, c = 0.1 - 1.0, c = 1.0 - 2.0, c = 1.0 - 3.0, c = 1.0

3.7.2. y = 1/(a + be CX ) Special case: a = 1, b = 1 gives sigmoidal curve 1. 2. 3. 4. 5. 6.

3.7.3. 1. 2. 3. 4. 5. 6.

a a a a a a

= 1.0, b = 1.0, c = 2.0 = 1.0, b = 1.0, c = 4.0 = 1.0, b = 2.0, c = 4.0 = - 2.0, b = 2.0, c = 2.0 = - 2.0, b = 2.0, c = 4.0 = - 2.0, b = 4.0, c = 4.0

y a a a a a a

= = = = = = =

ae bx + ce dx 1.0, b = 2.0, 1.0, b = 1.0, 1.0, b = 1.0, 0.1, b = 3.0, 0.1, b = 4.0, 0.1, b = 5.0,

c = -1.0, d = 3.0 c = -1.0, d = 3.0 c = -1.0, d = 5.0 c = 0.1, d = -3.0 c = 0.1, d = -2.0 c = 0.1, d = -1.0

125 3

3.7.1

3.7.1 6

5 4

3.7.2

3.7.2

654

3

2

3 2 1

3.7.3

3.7.3

CRC Standard Curves and Surfaces

126

3.7.4. 1. 2. 3. 4.

5. 6.

Y = l/(ae bX + ce dx ) a = 10.0, b = 2.0, c = -10.0, d = 3.0 a = 10.0, b = 1.0, c = -10.0, d = 3.0 a = 10.0, b = 1.0, c = -10.0, d = 5.0 a = 1.0, b = 3.0, c = 1.0, d = - 3.0 a = 1.0, b = 4.0, c = 1.0, d = - 2.0 a = 1.0, b = 5.0, c = 1.0, d = -1.0

3.7.5. y = c exp(ax 2 ) a < 1 gives Gaussian curve (also called normal curve)

1. 2.

a

= -1.0, c = 1.0

4.

a = - 2.0, c = 1.0 a = - 4.0, c = 1.0 a = 1.0, c = 0.3

5. 6.

a = a =

3.

2.0, c = 0.3 4.0, c = 0.3

3.7.6. y = c exp(l/ax) 1. a = 1.0, c = 0.2 2. a = 2.0, c = 0.2 3. a = 4.0, c = 0.2

127

3.7.4

3.7.4

4

3.7.5

3.7.5

3.7.6

128

CRC Standard Curves and Surfaces

3.7.7. y = c exp(1/ax 2 ) 1. a = 1.0, c = 0.1 2. a = 2.0, c = 0.1 3. a = 4.0, c = 0.1 3.7.8. y = c exp[l/(l - ax 2 )] 1. a = 2.0, c = 0.1 2. a = 4.0, C = 0.1 3. a = 8.0, C = 0.1 3.7.9. 1. 2. 3.

y = C exp[1/(l - alxl)] a = 2.0, C = 0.1 a = 4.0, C = 0.1 a = 8.0, C = 0.1

3.7.10. y = c[1 + exp(ax)]j[l - exp(bx)] 1. a = 1.0, b = 4.0, C = 0.02 2. a = 1.0, b = 1.0, C = 0.02 3. a = 4.0, b = 1.0, C = 0.02

129 3 2

3

3.7.7

3.7.8

32

3

3.7.9

1

2

3.7.10

1

2

130

CRC Standard Curves and Surfaces

3.8. HYPERBOLIC FUNCTIONS 3.8.1. y

=

0.1 sinh 5x

3.8.2. y

=

0.1 cosh 5x

Catenary

3.8.3. y

=

tanh 5x

3.8.4. y

=

0.1 coth 5x

3.8.5. y

=

sech 5x

3.8.6. y

=

0.1 csch5x

131

3.8.1

3.8.2

3.8.3

3.8.4

3.8.5

3.8.6

132

CRC Standard Curves and Surfaces

3.8.7. y = sinh 2 x 3.8.8. y

=

0.5 cosh 2 x

3.8.9. y

=

tanh 2 5x

133

3.8.8

3.8.7

3.8.9

134

CRC Standard Curves and Surfaces

3.8.10. y = 0.25/(sinh x cosh x) 3.8.11. y = sinh ax cosh bx 1. a = 0.5, b = 0.75 2. a = 1.0, b = 0.75 3. a = 1.0, b = 1.50 3.8.12. y = sinh ax sinh bx 1. a = 1.0, b = 1.5 2. a = 1.0, b = 2.0 3. a = 1.0, b = 3.0 3.8.13. y = 0.5 cosh ax cosh bx 1. a = 1.0, b = 1.25 2. a = 1.0, b = 2.00 3. a = 1.0, b = 4.00

135 3

3.8.11

3.8.10 3

3.8.12

2 1

3

3.8.13

2

2

136

CRC Standard Curves and Surfaces

3.9. INVERSE HYPERBOLIC FUNCTIONS 3.9.1. Y = 0.5 sinh -1 5x 3.9.2. y = 0.5 cosh- 1 5x 3.9.3. y = 0.2tanh- 1 x 3.9.4. y = coth- 1 5x 3.9.5. y = 0.2sech- 1 x 3.9.6. y = 0.2csch- 1

X

137

3.9.1

3.9.2

3.9.3

3.9.4

3.9.5

3.9.6

138

CRC Standard Curves and Surfaces

3.10. TRIGONOMETRIC AND EXPONENTIAL FUNCTIONS COMBINED 3.10.1. y = e ax sin(27Tbx) 1. a = -1.0, b = 4.0 2. a = - 2.0, b = 4.0 3.10.2. y = e ax COS(27Tbx) 1. a = -1.0, b = 4.0 2. a = - 2.0, b = 4.0

3.10.3. y = 0.5 e ax /sin(27Tbx) 1. a = -1.0, b = 4.0 2. a = - 2.0, b = 4.0 3.10.4. y = O.5e ax /COS(27Tbx) 1. a = - 1.0, b = 4.0 2. a = - 2.0, b = 4.0

139

3.10.2

3.10.1

~

ij

~~

V

~

~~

2 1

A

~~

3.10.3

~~

, A

~

~~

3.10.4

1 2

140

CRC Standard Curves and Surfaces

3.11. TRIGONOMETRIC FUNCTIONS COMBINED WITH POWERS OF X 3.11.1. y = x sin(27Tax) 1. a = 4.0 3.11.2. y = x COS(27Tax) 1. a = 4.0 3.11.3. y = x/sin(27Tax) 1. a = 4.0 3.11.4. y = x/COS(27Tax) 1. a = 4.0 3.11.5. y = [sin(27Tax)]j27Tax sinc function 1. a = 4.0 3.11.6. y = [cos(27Tax)]j27Tax 1. a = 4.0

141

3.11.1

,

v~~

I

~~

3.11.3

3.11.5

3.11.2

~~v

~ ~,

v~~

A

~~v

~~ ~~ 3.11.4

3.11.6

n

142

CRC Standard Curves and Surfaces

3.11.7. Y = x sin 2 (2'7Tax) 1. a = 4.0 3.11.8. Y = x cos 2 (2'7Tax) 1. a = 4.0 3.11.9. Y = 0.025[sin(2'7Tax)]jx 2 1. a = 4.0 3.11.10. Y = 0.01[cos(2'7Tax)]jx 2 1. a = 4.0 3.11.11. Y = 0.5 x/sin 2 (2'7Tax) 1. a = 4.0 3.11.12. Y = 0.5 xlcos 2 (2'7Tax) 1. a = 4.0

143

3.11.7

3.11.8

3.11.9

3.11.10

3.11.11

3.11.12

144

CRC Standard Curves and Surfaces

3.11.13. y = 0.5 x/[l 1. a = 4.0

+ sin(27Tax)]

3.11.14. Y = 0.5 x/[l 1. a = 4.0

+ cos(27Tax)]

3.11.15. y = 0.5 x/[l - sin(27Tax)] 1. a = 4.0 3.11.16. y = 0.5 x/[l - cos(27Tax)] 1. a = 4.0

145

I

~\

3.11.13

~~

\~

3.11.14

~

3.11.16

l \~

3.11.15

CRC Standard Curves and Surfaces

146

3.12. LOGARITHMIC FUNCTIONS COMBINED WITH POWERS OF X 3.12.1. y = x In ax 1. a = 1.0 2. a = 2.0 3. a = 4.0 3.12.2. y = x 2 In ax 1.

2. 3.

a a

=

a

=

=

1.0 2.0 4.0

3.12.3. y = 0.05/(x In ax) 1. a = 1.0 2. a = 2.0 3. a = 4.0 3.12.4. y = 0.005/(x 2 In ax) 1. a = 1.0 2. a = 2.0 3. a = 4.0 3.12.5. y = O.lln(ax)/x 1. a = 1.0 2. a = 3.0 3. a = 9.0 3.12.6. y = 0.5 x/In(ax) 1. a = 1.0 2. a = 3.0 3. a = 9.0

147

3.12.1

~.12.2

3

3

2

2

2

3

3.12.3

3.12.4

------3 2

3.12.5

3.12.6

(

148

CRC Standard Curves and Surfaces

3.12.7. Y = x In(ax + b) 1. a = 1.0, b = 2.0 2. a = 4.0, b = 2.0 3. a = 4.0, b = 4.0 4. a = 6.0, b = - 1.0 5. a = 4.0, b = - 1.0 6. a = 4.0, b = - 2.0 3.12.8. Y = O.l[ln(ax + b )]jx 1. a = 1.0, b = 2.0 2. a = 4.0, b = 2.0 3. a = 4.0, b = 4.0 4. a = 6.0, b = -1.0 5. a = 4.0, b = -1.0 6. a = 4.0, b = - 2.0 3.12.9. y = x In(x 2 1. a = 0.0 2. a = 0.5 3. a = 1.0

+ a2)

3.12.10. y = 0.5x In(x 2 1. a = 0.1 2. a = 0.3 3. a = 0.5

-

a2)

149 3

4

3 2

2

3.12.7

3.12.7

3.12.8

3.12.8

5

2

3

L-------------4--------------,~

3

3.12.9

3.12.10

150

CRC Standard Curves and Surfaces

3.13. EXPONENTIAL FUNCTIONS COMBINED WITH POWERS OF X 3.13.1. Y = 0.5 xe ax 1. a = 1.0 2. a = 2.0 3. a = 3.0 3.13.2. y = x 2 e ax 1. a = 1.0 2. a = 2.0 3. a = 3.0 3.13.3. Y = 4.0x 3e ax 1. a = 2.0 2. a = 4.0 3. a = 6.0 3.13.4. Y = 0.1 1. a = 1.0 2. a = 2.0 3. a = 3.0

eax Ix

3.13.5. Y = 0.03 e ax Ix 2 1. a = 2.0 2. a = 3.0 3. a = 4.0 3.13.6. Y = 0.01 e ax Ix 3 1. a = 3.0 2. a = 4.0 3. a = 5.0

151 3

2

1

3.13.1

3 2

3.13.2 321

3.12.3

~: 3.13.4

~:

I~: 3.13.5

1

3.13.6

152

CRC Standard Curves and Surfaces

3.13.7. y = ex exp(ax 2 ) 1. a = - 1.0, e = 1.0 2. a = - 2.0, e = 1.0 3. a = - 3.0, e = 1.0 4. a = 1.0, e = 0.1 5. a = 2.0, e = 0.1 6. a = 3.0, e = 0.1 3.13.8. y = ex 2 exp(ax 2 ) 1. a = - 1.0, e = 2.0 2. a = - 2.0, e = 2.0 3. a = - 3.0, e = 2.0 4. a = 1.0, e = 0.5 5. a = 2.0, e = 0.5 6. a = 3.0, e = 0.5

153 6

2

____~______~~------------3

3.13.7

3.13.7 65

2

3.13.8

3.13.8

4

154

CRC Standard Curves and Surfaces

3.14. HYPERBOLIC FUNCTIONS COMBINED WITH POWERS OF X 3.14.1. y

=

O.lx sinh5x

3.14.2. y = O.lx cosh 5x 3.14.3. y = x tanh 5x 3.14.4. Y = O.02(sinh5x)/x 3.14.5. Y = O.02(cosh5x)/x 3.14.6. Y = O.2(tanh5x)/x

")

155

3.14.1

3.14.2

3.14.3

3.14.4

3.14.5

3.14.6

156

CRC Standard Curves and Surfaces

3.15. COMBINATIONS OF TRIGONOMETRIC FUNCTIONS, EXPONENTIAL FUNCTIONS, AND POWERS OF X 3.15.1. y = 0.15xe aX sin(2'1Tbx) 1. a = 1.0, b = 4.0 2. a = 2.0, b = 4.0 3.15.2. y = 0.15xeaXcos(2'1Tbx) 1. a = 1.0, b = 4.0 2.

a

= 2.0, b = 4.0

3.15.3. Y = 0.1 e ax sin(2'1Tbx)/x 1. a = 1.0, b = 4.0 2. a = 2.0, b = 4.0 3.15.4. 1. 2.

y

= 0.1 e ax cos(2'1Tbx)/x

= 1.0, b = 4.0 a = 2.0, b = 4.0

a

157

2'~~~~~~~~~~~L4-+-+~ 1

2 2

3.15.1

3.15.2

2

2

3.15.3

3.15.4

158

CRC Standard Curves and Surfaces

3.16. MISCELLANEOUS TRANSCENDENTAL FUNCTIONS 3.16.1. Y = a cosh~l(a/x) - (a 2 Tractrix

1. 2. 3.

a = 1.00 a = 0.75 a = 0.50

3.16.2. Y = x cot(-rrx/2a) Quadratrix of Hippias

1. 2. 3.

a = 0.25 a = 0.35 a = 0.45

3.16.3. Y = 1 - e ax Exponential Ramp

1. 2.

3.

-2.0 -4.0 a = -6.0 a

=

a

=

3.16.4. Y

1. 2.

3. 4.

5. 6.

=

cO -

2ax 2 )exp(ax 2 )

a = - 3.0, c = 1.0 a = - 6.0, c = LO a = - 9.0, c = 1.0 a = 3.0, c = 0.1 a = 6.0, c = 0.1 a = 9.0, c = 0.1

-

X 2 )1/2

159 2

\ 3.16.1

1

2

65

4

3.16.2

--====~1

3.16.3

3.16.4

3.16.4

3

160

CRC Standard Curves and Surfaces

3.16.5. Y = c arctan(e aX ) - b Special case: a = 1, b = 1T12, c = 2 gives Gudermannian function

1. 2. 3.

a = 1.0, b = 1T14, c = 1.0 a = 3.0, b = 1T1 4, c = 1.0 a = 10.0, b = 1T14, c = 1.0

3.16.6. Y = c sin{ b

~da [( (b -

a)

~ +a

r-

Sweep signal (linear) 1.

a = 5.0, b = 25.0, c = 0.5, d = 1.0

3.16.7. Y = sin(a1Tx) arcsin x 1. a = 1.0 2. a = 2.0 3. a = 3.0 3.16.8. y = c(bx)alnbx 1. a = 2.0, b = 2.0, c = 0.1 2. a = 2.0, b = 4.0, c = 0.1 3. a = 4.0, b = 4.0, c = 0.1 3.16.9. y = c/(bx)alnbx 1. a = 2.0, b = 2.0, c = 1.0 2. a = 2.0, b = 4.0, c = 1.0 3. a = 4.0, b = 4.0, c = 1.0

a 2 ]}

161

-----~

3.16.6

3.16.5

3

3

2

3.16.8

3.16.7

3.16.9

2

162

CRC Standard Curves and Surfaces

3.16.10. Y = Isin(a1Tx)IItan(a'ITx)l+l 1. a = 2.0 3.16.11. y = exp[b cos(a1Tx) - b] 1. a = 1.0, b = 2.0 2. a = 1.0, b = 10.0 3. a = 1.0, b = 50.0 3.16.12. y = signum[siIi(a1Tx)]lsin(a1Tx)1 1/ 1. a = 1.0, b = 10.0

b

3.16.13. y = sin(; sin(; sin( ... sin( a;x ) ... )))

Let n be the order of nesting of the sine function. 1.

a = 8, n = 5

163

3.16.11

3.16.10 r--

,,....-

,...--

'--

3.16.12

3.16.13

~

'----

'----

164

CRC Standard Curves and Surfaces

3.17. TRANSCENDENTAL FUNCTIONS EXPRESSIBLE IN POLAR COORDINATES 3.17.1. r = ce ao ~ In[(x 2 + y2)/c 2] - a arctan(y Ix) = 0 Logarithmic spiral (also called equiangular spiral or logistique)

1. 2.

a = 0.1, c = 0.10; 0 < 8 < 77T a = 0.2, c = 0.01; 0 < 8 < 77T

3.17.2. r = c8 1/ m (x 2 + y2)m/2 - cmarctan(ylx) Archimedean spirals (m =1= 0)

1. 2. 3. 4.

c c

0.04, 0.20, c = 1.00, c = 0.50, = =

=

0

m = 1; 0 < 8 < 87T (Archimedes' spiral) m = 2; 0 < 8 < 87T (Fermat's spiral) m = -1; 1.00 < 8 < 67T (hyperbolic spiral) m = -2; 0.25 < 8 < 67T (lituus)

165 2

3.17.1

3.17.1 2

3.17.2

3.17.2

3

4

3.17.2

3.17.2

CRC Standard Curves and Surfaces

166

3.17.3. r = c cos me (x 2 + y2)1/ 2 Rhodonea (also called rose)

1. 2.

c = 1.0, m = 4.0; 0 < c = 1.0, m = 3.0; 0
0] Recurrence relation:

with

Ho(x)

=

1

0.lHo(5x) 0.lH 1(5x) 0.lHi5x)/23 0.lH3(5x)/3 3 0.lHi5x)/4 3 0.lHs(5x)/5 3

O. 1. 2. 3. 4. 5.

4.1.7. Gegenbauer Polynomials C:(x) Domain: [ -1 < x < 1] Recurrence relation:

C:+1(x)

=

2(n + a)xC: - (n + 2a - 1)C:_ 1 n + 1

with

CQ(x) = 1 Cf(x) = 2ax Special cases: a

=

a

=

O. 1. 2. 3. 4. 5. 6. 7.

1.0 gives Chebyshev polynomials of the second kind 0.5 gives Legendre polynomials

0.08C5(x) 0.08C~(x)

0.08Ci(x) 0.08Ci(x) 0.08Cl(x) 0.08C}(x) 0.08Cl(x) 0.08C?(x)

191 54 3

1""7''--79.'H----- 0

4.1.6 46

4.1.7

4.1.7

192

CRC Standard Curves and Surfaces

4.1.8. Jacobi Polynomials p:,b(X) Domain: [ - 1 < x < 1] Recurrence relation: (2n

p:+~

+ a + b + 1)[(a 2 -

b 2)

+

-2(n

=

+ a + b + 2)(2n + a + b)x]Pna,b + a)(n + b)(2n + a + b + 2)P::....~

(2n

-----------2~(~n-+~I~)~(n--+-a~+-b~+~I)~(~2-n-+~a-+--b~)------~~

with PO,b

=

1

pa,b _ a - b 1

1-0. 1-1. 1-2. 1-3. 1-4. 1-5. 3-0. 3-1. 3-2. 3-3. 3-4. 3-5.

-

P o l/2,1/2(X)

+

(a

2

+ b + 2)x

P 3- l / 2, 1/2(X) P4- l / 2, 1/2(X) P5- l / 2, 1/2(X)

2-0. 2-1. 2-2. 2-3. 2-4. 2-5.

P6,-1/2(X) Pl' -1/2(X) Pi' -1/2(X) pj' -J/2(X) N' -J/2(X) pJ' -J/2(X)

4-0. 4-1. 4-2. 4-3. 4-4. 4-5.

P 1 l/2,1/2(X)

P:i 1/2, 1/2(X)

Po 1/2, lex)

Pl

l / 2,1(X)

Pi 1/2, lex) P j l/2,1(X) P4- l / 2,1(X) P 5- l / 2, l(X) P6,1/2(X) Pl,1/2(X) pi,1/2(X) pj,1/2(X) pl,1/2(x) pJ,1/2(X)

193 ~--~----------__---------------1-0

---T--~--------r_---------------2-0

1-1

2-1

4.1.8

4.1.8 -.-r------------~----_r--_r~n__4-0

----------------~~----_r_._rr__3-0

3-5

4-1

4.1.8

4.1.8

194

CRC Standard Curves and Surfaces

4.2. NON-ORTHOGONAL POLYNOMIALS 4.2.1. Bernoulli Polynomials Bn(x) Domain: [-00 < x < 00] Recurrence relation: none O. 1. 2.

3. 4.

5.

B o(2x) B 1(2x) Bi2x) Bi2x) B/2x) B 5 (2x)

4.2.2. Euler Polynomials En(x) Domain: [-00 < x < 00] Recurrence relation: none O. 1.

E o(2x) E 1(2x)

2.

Ei2x) Ei2x) E/2x) E 5 (2x)

3. 4.

5.

195 ------~~,-------~--o

531

4.2.1 ----~\T~,-------~~O

5 3 1

4.2.2

196

CRC Standard Curves and Surfaces

4.2.3. Neumann Polynomials 0n(x) Domain: [x > 0] Recurrence relation (for n > 1):

with I

Oo(x) =

X-

Ol(X)

l 2 x

=

I

Oix) = -

x

O. 1. 2. 3. 4.

S.

4

+ 3" x

O.OSOo(Sx) O.OSOl(SX) O.OSOzCSx) O.OSOiSx) O.OSOiSx) O.OSOs(Sx)

4.2.4. Schlafli Polynomials Sn(x) Domain: [x > 0] Relation to Neumann polynomials: 2xOn( x) - 2 cos 2 ( mT /2) S (x) = ---'..:...-'.......:....----'---'--~ n n

Note: So = 0

1. 2. 3. 4. S.

O.OSSl(SX) O.OSSzCSx) O.OSSiSx) O.OSSiSx) O.OSSs(Sx)

197 012 3 4

5

4.2.3 1 2 3 4

4.2.4

5

198

CRC Standard Curves and Surfaces

REFERENCES 1. Abramowitz, M., and I. A. Stegun, Eds., Handbook of Mathematical Functions, National Bureau of Standards, U.S. Department of Commerce, Washington, D.C., 1964. 2. Beyer, W. H., Ed., Handbook of Mathematical Sciences, 6th Ed., CRC Press, Boca Raton, Florida, 1987.

199

Chapter 5

SPECIAL FUNCTIONS IN MATHEMATICAL PHYSICS The curves in this chapter are found in Abramowitz and Stegun, l and the names and notation used here conform with that reference. The approximations necessary to compute these curves are also given there; for purposes of illustrating the curves, the approximations were encoded into computer algorithms such that accuracy was attained to at least three significant figures for all plotted points of a curve. Such accuracy is sufficient for illustrative purposes and was efficiently achieved in all cases. The curves shown in this chapter are only representative, and the interested reader should, when necessary, consult the above reference, or similar ones such as Jahnke and Emde,2 Beyer,3 and Gradshteyn and Ryzhik,4 for a complete treatment of these curves. The reader should be aware that many of the functions are defined for a complex argument, while they are only plotted for a real argument in this chapter, thus showing only a vertical slice of the threedimensional surface over the complex plane.

200

CRC Standard Curves and Surfaces

5.1. EXPONENTIAL AND RELATED INTEGRALS 5.1.1. Exponential Integral En(x) = gee -xl Itn) dt Domain: [x > 0] Recurrence relation: En+1(x) = (l/n)[e-X - xEn(x)], n = 1,2,3, ... , with Eo(x) = e- XIx O. 1. 2. 3. 4. 5.

6. 7.

Eo(x) E/x) EzCx) Eix) E/x) Es(x) E 6(x) Eix)

5.1.2. Exponential Integral Ei(x) Domain: [x > 0] 1.

=

- f~je-llt)

dt

0.5Ei(x)

5.1.3. Alpha Integral an(x) = f~tne-Xl dt Domain: [x > 0] Recurrence relation: a n+l(x) = (llx)[e- X + (n + l)a n(x)], n = 0,1,2, ... , with ao(x) = e- xIx O. 1. 2. 3. 4. 5. 6. 7.

0.2a o(5x) 0.2al(5x) 0.2azC5x) 0.2ai5x) 0.2a/5x) 0.2a s(5x) O.2a6(5x) 0.2a 7 (5x)

201 2

o

~ 5.1.2

5.1.1

5.1.3

202

CRC Standard Curves and Surfaces

5.1.4. Beta Integral f3n(x) Domain: [x > 0] Recurrence relation:

= f~ltne-xt

dt

n=0,1,2, ... with f3 o(x) O. 1. 2. 3. 4. 5. 6. 7.

0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1

=

(2/x)sinh x

f3o(5x) f31(5x) f3zC5x) f3i5x) f3i5x) f3sC5x) f36(5x) f37(5x)

5.1.5. Logarithmic Integralli(x) Domain: [x > 0] 1.

0.005li(1000x)

203

1 357

5.1.4

5.1.5

204

CRC Standard Curves and Surfaces

5.2. SINE AND COSINE INTEGRALS 5.2.1. Sine Integral Six = !o[(sint)/t]dt Domain: [x > 0] 1.

0.5Si(20x)

5.2.2. Cosine Integral Ci x = 'Y Domain: [x > 0] 1.

+ In x + !o[(cos t

Ci(20x)

5.2.3. Sici Spiral x = c Ci t; Y = c[Si t - 11"/2] 1.

c = 0.5, 0 < t < 611"

- l)/t] dt

205

5.2.1

5.2.2

5.2.3

206

CRC Standard Curves and Surfaces

5.3. GAMMA AND RELATED FUNCTIONS 5.3.1. Gamma Function f(x) = J;tx-1e- t dt Also called Euler's integral of the second kind Domain: [-00 < x < 00] Recurrence relation: f(x + 1) = xf(x) 1.

0.2f(5x)

5.3.2. Complex Gamma Function f(x + iy) Domain: [-00 < x < 00, -00 < y < 00] 1. 2.

Contours of the surface of If(x + iy)l; - 5 < x < 5, -1 < y < 1 Contours of the surface of If(x + iy)l; - 5 < x < 5, - 5 < y < 5

5.3.3. Beta Function B(x, w) = JJt x - 1(1 - t)w-l dt Also called Euler's integral of the first kind Domain: [-00 < x < 00] Relation to gamma function: B(x, w) = f(x)f(w)/f(x + w) 1. 2. 3. 4.

0.5 0.5 0.5 0.5

B(5x, 1) B(5x,2) B(5x,3) B(5x,4)

5.3.4. Psi Function !/I(x) = [df(x)/dx]jf(x) Also called digamma function Domain: [-00 < x < 00] 1. 0.2!/1(5x)

207

u 5.3.1 2

o

o

5

5.3.2 4

5

5.3.2

2

I

~

I

( 3

5.3.3

5.3.4

208

CRC Standard Curves and Surfaces

5.4. ERROR FUNCTIONS 5.4.1. Error Function Erf(x) Domain: [-00 < x < 00]

=

(2/7T 1/ 2 ) It exp( - t 2) dt .

1. Erf(2x) 5.4.2. Complementary Error Function Erfc(x) = 1 - Erf(x) Domain: [-00 < x < 00] 1.

0.5Erfc(2x)

5.4.3. Derivatives of the Error Function Erf(n)(x) = dn[Erf(-!)}jdXn Domain: [-00 < x < 00] 1. 0.40 Erf(l)(2x) 2. 0.20 Erf(2)(2x) 3. 0.05 Erf(3)(2x)

209

5.4.1

5.4.2

3

~------~----~---+------~~

5.4.3

210

CRC Standard Curves and Surfaces

5.5. FRESNEL INTEGRALS 5.5.1. First Fresnel Integral Sex) = Domain: [-00 < x < 00] 1.

S(5x)

5.5.2. Second Fresnel Integral C(x) Domain: [-00 < x < 00] 1.

=

It COS(7Tt 2 j2) dt

C(5x)

5.5.3. Cornu's Spiral x 1.

It sin(7Tt 2 j2) dt

-4
0] Recurrence relation:

2n In+1(x) = In-1(x) - x1n(x)

n

=

0,1,2, ...

Symmetry: Ln(x) = In(x) O. 1. 2.

3. 4. 5.

0.1 0.1 0.1 0.1 0.1 0.1

I o(10x) Ij(lOx) Ii10x) 13(lOx) I/lOx) Is(lOx)

5.8.2. Modified Bessel Function Kn(x) Domain: [x > 0] Recurrence relation:

n = 0,1,2, ...

O. 1. 2. 3. 4.

5.

0.1 0.1 0.1 0.1 0.1 0.1

K o(5x) K 1(5x)

KzC5x) Ki5x) K/5x) K s(5x)

221 012345

5.8.1 12 3 4

5.8.2

5

222

CRC Standard Curves and Surfaces

5.9. KELVIN FUNCTIONS 5.9.1. Kelvin Function bern(x) Domain: [x > 0] Recurrence relation: 2l/2n

.

bern+l(x) = - -x- [bern(x) - beln(x)] - bern_leX),

n=1,2,3, ...

Symmetry: becn(x) = (_l)n bern(x) O. 1. 2. 3. 4. 5.

0.1 beroC8x) 0.1 ber l(8x) 0.1 beri8x) 0.1 beri8x) 0.1 beri8x) 0.1 bers(8x)

5.9.2. Kelvin Function bein(x) Domain: [x > 0] Recurrence relation: .

2l/2n.

.

beln+l(x) = - -x- [beln(x) + bern(x)] - beln_l(x), Symmetry: beLn(x) = (_l)n bein(x) O. 0.1 bei o(8x) 1. 0.1 bei l(8x) 2. 0.1 bei z(8x) 3. 0.1 bei 3 (8x) 4. 0.1 beii8x) 5. 0.1 beisC8x)

n=1,2,3, ...

223 1

40

3 2

5.9.1

o 5.9.2

3

224

CRC Standard Curves and Surfaces

5.9.3. Kelvin Function kern(x) Domain: [x > 0] Recurrence relation: 2l/2n

kern+l(x)

= -

.

-x-[kern(x) - keln(x)] - kern_leX),

Symmetry: kecn(x)

=

n=1,2,3, ...

(_l)n kern(x)

O. ker o(8x) 1. keri8x) 2. keri8x) 3. keri8x) 4. keri8x) 5. kers(8x) 5.9.4. Kelvin Function kein(x) Domain: [x > 0] Recurrence relation:

n=1,2,3, ...

O. 1. 2. 3. 4. 5.

kei o(8x) kei l (8x) kei 2 (8x) keii8x) keii8x) kei s(8x)

225 035

5.9.3 245

3

5.9.4

226

CRC Standard Curves and Surfaces

5.10. SPHERICAL BESSEL FUNCTIONS 5.10.1. Spherical Bessel Functions of the First Kind, jix) Domain: [x > 0] Relation to Bessel Function: jn(x) = (7T /2x)1/z In+1/ix) Recurrence relation: .

( ) = 2n x+ 1 in . (X) - In-l . (X) ,

In+l x

o. 1. 2. 3.

n = 0,1,2, ...

jo(20x) jl(20x) ji20x) M20x)

5.10.2. Spherical Bessel Functions of the Second Kind, yix) Domain: [x > 0] Relation to Bessel Function: yix) = (7T /2x)1/ZYn+l/ix) Recurrence relation: Yn+l(x) =

2n

+1

X

yn(x) - Yn-l(X),

n = 0,1,2, ...

Symmetry: y-n(x) = (_l)l-njn_l(X) O. 1. 2. 3.

yaC20x) Yl(20x) Yz(20x) yi20x)

5.10.3. Spherical Bessel Functions of the Third Kind, h~l)(X) and M!')(x) Domain: [x > 0] Relation to Hankel Function: h~'Z)(x) = (7T/2x)1/zH~~~jix) Recurrence relation: h(l,Z)(X) n+l

=

2n

+ 1 h(l,Z)(X)

X

O. 1.

Ihbm)(20x)l, m = 1,2 Ihim)(20x)l, m = 1,2

2. 3.

Ih~m)(20x)l, Ih~m)(20x)l,

m = 1,2 m = 1,2

n

- h(l,Z)(X)

n-l,

n = 0,1,2, ...

227

o

5.10.2

5.10.1 13

02

5.10.3

228

CRC Standard Curves and Surfaces

5.11. MODIFIED SPHERICAL BESSEL FUNCTIONS 5.11.1. Modified Spherical Bessel Functions of the First Kind, (rr /2X)1/2 In + 1/2(X) Domain: [x > 0]

Recurrence relation: n=0,1,2, ...

O. 1. 2. 3.

4. 5.

0.1 0.1 0.1 0.1 0.1 0.1

(rr /20x )1/2 (rr /20x )1/2 (rr/20x)1/2 (rr/20x)1/2 (rr /20X)1/2 (rr/20x)1/2

I 1/ 2(10x) I3/zC10x) Is/zC10x) I7/i10x) I9/zClOx) I l1 / 2(10x)

5.11.2. Modified Spherical Bessel Functions of the Second Kind, (rr /2X)1/2Ln_l/ix) Domain: [x > 0]

Recurrence relation: L n -3j2(X)

O. 1. 2.

3. 4. 5.

0.1 0.1 0.1 0.1 0.1 0.1

=

Ln+1/2(X) -

(rr/20x)l/2 (rr /20X)1/2 (rr /20x )1/2 (rr /20X)1/2 (rr/20x)1/2 (rr/20x)1/2

2n

+1

x

L n -l/ 2(x),

n

=

0,1,2, ...

L 1/ 2(10X) L3/ilOx) Ls/i10x) L 7/ 2(lOx) L 9/ 2(10X) Ll1/ilOx)

5.11.3. Modified Spherical Bessel Function of the Third Kind, (rr /2X)1/2Kn+1/ix) Domain: [x > 0]

Recurrence relation: n=0,1,2, ...

O. 1. 2. 3. 4. 5.

(rr/20x)1/2 (rr/20x)1/2 (rr/20x)1/2 (rr/20x)1/2 (rr/20x)1/2 (rr /20X)1/2

K 1/ 2(10X) K 3 / 2(lOx) Ks/zC10x) K7/zC10x) K9/ilOx) K l1 / 2(10x)

229 024 012345

1 3 5

5.11.2

5.11.1 012345

5.11.3

230

CRC Standard Curves and Surfaces

5.12. AIRY FUNCTIONS 5.12.1. Airy Function Ai(x) Domain: [-00 < x < 00] 1.

Ai(lOx)

5.12.2. Airy Function Bi(x) Domain: [-00 < x < 00] 1.

Bi(lOx)

5.13. RIEMANN FUNCTIONS 5.13.1. Zeta Function (x) Domain: [-00 < x < 00] 1.

0.21(5x)1

5.13.2. Zeta Function I(t + iy)1 The line x = t in the complex plane is the critical line of the zeta function. Domain: [-00 < y < 00] 1.

0.21(1/2

+ i50y)1

5.13.3. Complex Zeta Function (x + iy) Domain: [-00 < x < 00, -00 < y < 00] 1.

Contours of the surface I(x

+ iy)l; -4 < x < 4, 0 < y < 15

5.14. PARABOLIC CYLINDER FUNCTIONS 5.14.1. Half-Integer Orders Solving y" - (x 2 /4 Domain: [x > 0] 1.

0.5y(5x)

+ a)y

=

0

231

5.12.1

5.12.2

5.13.1

5.13.2

5.14.1

232

CRC Standard Curves and Surfaces

5.15. ELLIPTIC INTEGRALS 5.15.1. Elliptic Integral of the First Kind, F( 0] 1. P(lOx): a = 0, b = 0.5 2. P(lOx): a = 0, b = 1.0 3. P(lOx): a = 0, b = 2.0 6.2.10. Maxwell, P(x) = (4/171/2a 3 )x 2 exp( -x 2/a 2) Domain: [x > 0] 1. P(lOx): a = 1 2. P(10x): a = 2 3. P(lOx): a = 3 6.2.11. Normal (Gaussian), P(x)

=

1 (217)1/2b

Domain: [-00

<x < 00]

1. P(lOx): a = 0, b = 1 2. P(10x): a = 0, b = 2 3. P(lOx): a = 0, b = 3 6.2.12. Pareto, P(x) = (x/b)(l Domain: [x > 0] 1. 5.0P(10x): a = 2, b = 1 2. 3. 4. 5. 6.

5.0P(10x): a = 2, b = 2 5.0P(lOx): a = 2, b = 3 10.0P(lOx): a = 4, b = 1 10.0P(10x): a = 4, b = 2 10.0P(lOx): a = 4, b = 3

+ x/b)-a-1

exp { _ [( x - a) /b ]2 } 2

253

6.2.10

6.2.9

6.2.11

123

6.2.12

6.2.12

254

CRC Standard Curves and Surfaces

6.2.13. Rayleigh, P(x) = a12x exp[ _

(x~a)2]

Domain: [x > 0] 1. P(lOx): a 2. P(10x): a 3. P(lOx): a

=

=

1 2

=3

6.2.14. Snedecor's F, P(x)

( mm/2nn/2)

=

Domain: [x > 0] 1. 2. 3. 4. 5. 6.

P(5x): P(5x): P(5x): P(5x): P(5x): P(5x):

m m m m m m

= = = = = =

5, n = 10 15, n = 10 50, n = 10 5, n = 20 15, n = 20 50, n = 20

B( m12, n12) x(m-2)/2(n + mx)-(m+n)/2

255

6.2.13

6.2.14

6.2.14

256

CRC Standard Curves and Surfaces

6.2.15. Student's t, P(x) Domain: [-00 < x < 00]

1 =

BG,

n 1/ 2

(. x 2 )- 0] 1. 2. 3. 4. 5. 6.

P(5x): P(5x): P(5x): P(5x): P(5x): P(5x):

a a a a a a

= 1, b = 1, b = 1, b = 2, b = 2, b =

2, b

= 1 = 2 = 3 = 2 = 3 =

4

257

3

6.2.15 3 6

6.2.16

6.2.16

258

CRC Standard Curves and Surfaces

6.3. SAMPLING DISTRIBUTIONS The following sampling distributions are expressed as integrals of a density function. By definition, at the upper limit the integral equals unity; therefore, the distributions are plotted so that the maximum is always unity. The actual domain of the sampling variable is as listed. 6.3.1. Normal Distribution P(X) =

11/2

(27T)

b

X

I x exp { -

=

[n 1/ 2BG, n/2)]-1

_

[(X-a)/b]2} 2

00

dx

< X < 00]

Domain: [-00

1. P(SX): a = 0, b = O.S 2. P(SX): a = 0, b = 1.0 3. P(SX): a = 0, b = 2.0 6.3.2. Student t Distribution P(tln)

Domain: [-00

< t < 00]

1. pest): n

2

=

+ (x 2/n)]-(n+l)/2 dx

X

foo[1

=

[2 n/ 2f(n/2)]-1

2. pest): n = S 3. peSt): n = 99

6.3.3. Chi-Square Distribution P(x 2In) Domain: X 2 >

X

°

jX x (n-2)/2 e -X/2 dx 2

o

1. P(2SX2): n = 2 2. P(2SX 2): n = 6 3. P(2Sx 2): n = 16 m/2 n/2

· ·b· P(FI )m n 634 . . . FD lstn utlOn m, n - B(m/2, n/2)

Domain: F> 1. P(SF): 2. P(SF): 3. P(SF): 4. P(SF): S. P(SF): 6. P(SF):

m m m m m m

°

(n

= 2, n = 10 = 6, n = 10 =

20, n

=

10

= 2, n = 20 = 6, n = 20 = 20, n = 20

j0Fx (m-2)/2

+ mx)-(m+n)/2 dx

259

6.3.2

6.3.1

6.3.3

6.3.4

. 6.3.4

261

Chapter 7

THREE-DIMENSIONAL CURVES As opposed to curves which lie wholly in a plane (called "plane curves"), certain curves occupy three dimensions (called "skew curves"). All three-dimensional curves must necessarily be expressed in parametric form: x =

f(t)

y =

get)

z=h(t) Because there are innumerable variations of the functions f, g, and h, three-dimensional curves can assume a wide variety in appearance. Only those curves having some accepted significance and use are illustrated here. Many interesting and useful three-dimensional curves can be generated simply by adding a z variation of some sort to the curves given in the previous chapters, after they are put into parametric form. The curves in this chapter are plotted as points (x p' yp) projected on a plane which is normal to the vector between the origin (0,0,0) and the viewpoint and which passes through the origin. The projection used is the perspective one (see Foley and VanDam l for a full treatment of projections). If the viewing point is at large distance relative to the projected points (as is the case in this chapter), then the view approaches the parallel one, which is given by the transformations xp = -x sin e + y cos e

yp = -

x cos

e cos 4> - y sin e cos 4> + z sin 4>

where (x, y, z) are the coordinates of the point on the curve prior to projection and (e, 4» are the angles in spherical coordinates (see Section 1.3) of the vector normal to the projection plane. The three axes are plotted with solid lines between the limits of -1.0 and + 1.0, with the positive z axis up.

262

CRC Standard Curves and Surfaces

7.1. HELICAL CURVES 7.1.1. Circular Helix This is also called the right helicoid: x

=

a sin t

y = a cos t

z 1.

a = 0.5,

C

=

t/(21TC)

= 5.0; 0 < t < 101T; viewpoint = (40, - 50,20)

7.1.2. Elliptical Helix x

=

a sin t

y

=

b cos

t

z = t/(21TC) 1.

a = 0.3, b = 1.0,

C

= 5.0; 0 < t < 101T; viewpoint = (40, - 50,20)

7.1.3. Conical Helix

x = (at/21Tc)sint y = (at /21TC )cos t z = t/(21TC)

1.

a = 0.5,

C

= 5.0; 0 < t < 101T; viewpoint = (40, - 50,20)

263

7.1.1

7.1.2

7.1.3

264

CRC Standard Curves and Surfaces

7.1.4. Spherical Helix x = sin[tj(2c)]cos t y

= sin[tj(2c)]sin t

z = cos[tj(2c)] 1.

c = 5.0;

°
c gives oblate spheroid b < c gives prolate spheroid

1. a = 1.00, b = 1.00, c = 0.5; viewpoint = (4, - 5,2) 2. a = 0.50, b = 0.50, c = 1.0; viewpoint = (4, -5,2) 8.3.3. z = (x 2

+ y2)l/2

x2

Cone

1. Viewpoint = (4, - 5,2)

+ y2

-

Z2

=

°

°

279

8.3.1 2

8.3.2

8.3.2

8.3.3

280

CRC Standard Curves and Surfaces

8.3.4. z = c(x 2/a 2 + y2/b 2)1/2 x 2/a 2 + y2/b 2 - Z2/C2 = 0 Elliptic cone (circular cone if a = b) 1. a = 0.5, b = 0.5, c = 1.00; viewpoint = (4, -5,2) 2. a = 1.0, b = 1.0, c = 0.50; viewpoint = (4, - 5,2) 8.3.5. z = c(x 2/a 2 + y2/b 2 - 1)1/2 x 2/a 2 + y2/b 2 - Z2/C2 - 1 Hyperboloid of one sheet

=

0

=

0

1. a = 0.1, b = 0.1, c = 0.2; ±z = cm; viewpoint = (4, - 5,2) 2. a = 0.2, b = 0.2, c = 0.2; ±z = cm; viewpoint = (4, - 5,2) 8.3.6. Z = c(x 2/a 2 + y2/b 2 + 1)1/2 x 2/a 2 + y2/b 2 - Z2/C2 + 1 Hyperboloid of two sheets

1. a = 0.125, b = 0.125, c = 0.2; ±z = cm; viewpoint = (4, - 5,2) cm; viewpoint = (4, -5,2)

2. a = 0.25, b = 0.25, c = 0.2; ±z =

281

2

8.3.4

8.3.4

2

8.3.5

8.3.5

2

8.3.6

8.3.6

282

CRC Standard Curves and Surfaces

1. a = 1.0, b = 1.0, 2. a = 1.0, b = 1.0,

1. a = 1.0, b = 1.0, 2. a = 1.0, b = 1.0,

C C

C

C

= 0.5; viewpoint = (1, - 5,2) = 2.0; viewpoint = (1, - 5,2)

= 0.5; viewpoint = (1, - 5,2) = 2.0; viewpoint = (1, - 5,2)

283

2

8.4.1 8.4.1 2

8.4.2 8.4.2

284

1. a 2. a

1. a 2. a

CRC Standard Curves and Surfaces

= =

= =

1.0, b 1.0, b

=

1.0, b 1.0, b

=

=

=

1.0, c 1.0, c

=

1.0, c 1.0, c

=

=

=

0.5; viewpoint 2.0; viewpoint

=

0.5; viewpoint 2.0; viewpoint

= (-

=

(2, - 4, 1) (2, - 4, 1)

= (-

4,3,2) 4,3, 2)

285 2

8.5.1

8.5.1 2

8.5.2

8.5.2

286

CRC Standard Curves and Surfaces

8.6. MISCELLANEOUS FUNCTIONS 8.6.1. z Torus

=

{a 2 - [(x 2

+ y2)1/2

b ]2}1/2

-

1. a = 0.2, b = 0.8; ±z = 2a; viewpoint = (4, - 5,2) 8.6.2. z = c(x 3 Monkey saddle

x3

3xy2)

-

3xy2 -

1. c = 1.0; viewpoint = (5,3,3) 8.6.3. z =

Cxy2

Cxy2 -

Z

= 0

1. c = 1.0; viewpoint = (5,3,3) 8.6.4. z = cx 2 y2 cx 2 y2 Crossed trough

-

Z

= 0

1. c = 4.0; viewpoint = (2, - 5,3)

zjc = 0

8.6.1

8.6.2

8.6.3

8.6,4

288

CRC Standard Curves and Surfaces

8.6.5. z = (ax 2 + by2)j(X 2 + y2) Conoid of Plucker or cylindroid

ax 2 + by2 - ZX2 - zy2 = 0

1. a = - 0.5, b = 0.8; viewpoint = (5, - 3,2)

1. a = 1.5, b = 1.0; viewpoint = (- 3, - 4,2) 2. a = 1.5, b = 3.0; viewpoint = ( - 3, - 4,2)

289

8.6.5 2

8.6.6

8.6.6

291

Chapter 9

TRANSCENDENTAL SURFACES The perspective projection described at the beginning of Chapter 7 is used for the figures in this chapter. The surface representation is as described at the beginning of Chapter 8. The bounding box, shown with most figures of this chapter, has limits of - 1 to + 1 for all three axes, unless noted otherwise. The true aspect ratio of all figures is preserved. Wherever the surfaces intersect the top or bottom of the bounding box, they are not accurately represented by the method used here.

292

CRC Standard Curves and Surfaces

9.1. TRIGONOMETRIC FUNCTIONS 9.1.1. z 1.

=

=

=

C

C

C

= 0.25; viewpoint = (5, - 4,4)

cos(27Taxy) C

= 0.25; viewpoint = (5, - 4,4)

sin(27Tax)sin(27Tby)

a = 2.0, b = 1.0,

9.1.6. z = 1.

c sin(21Taxy)

a = 3.0,

9.1.5. z 1.

c cos[21Ta(x 2 + y2)1/2]

a = 3.0,

9.1.4. z = 1.

+ y2)1/2]

a = 3.0, c = 0.25; viewpoint = (5, - 4,4)

9.1.3. z 1.

c sin[21Ta(x 2

a = 3.0, c = 0.25; viewpoint = (5, - 4,4)

9.1.2. z 1.

=

C

C

= 0.25; viewpoint = (5, - 4,4)

cos(27Tax)cos(21Tby)

a = 2.0, b = 1.0,

C

= 0.25; viewpoint = (5, - 4, 4)

293

~1.1

~12

~13

~lA

~lS ~1.6

294

CRC Standard Curves and Surfaces

9.2. LOGARITHMIC FUNCTIONS 9.2.1. z = c InCalxl 1.

a

=

1.0, b

=

+ blyl) 2.0, c

=

0.5; viewpoint

=

(4, -4,6)

=

0.2; viewpoint

=

(4, - 4,5)

9.2.2. z = c In(ax 2 + by2) 1.

a

9.2.3. z 1.

=

=

1.0, b

=

2.0, c

c In(lxyl)

c = 0.2; viewpoint = (4, - 4, 5)

295

9.2.2

9.2.1

9.2.3

CRC Standard Curves and Surfaces

296

9.3. EXPONENTIAL FUNCTIONS 9.3.1. z = c exp(ax

1.

a

+ by)

= 2.0, b = 2.0, c = 0.25; viewpoint = ( - 3, - 5,3)

9.3.2. z = c exp(ax 2 + by2)

1. 2. 3.

a = 1.0, b = 0.5, c = 0.25; viewpoint = (5, - 3,3) a = 1.0, b = - 0.5, c = 0.25; viewpoint = (5, - 3,3) a = - 2.0, b = - 1.0, c = 1.00; viewpoint = (5, - 3, 3)

9.3.3. z = c exp(axy)

1.

a = 1.0, c = 0.35; viewpoint = (5, - 3, 2)

297

9.3.2

9.3.1

3

2

9.3.2

9.3.2

9.3.3

CRC Standard Curves and Surfaces

298

9.4. TRIGONOMETRIC AND EXPONENTIAL

FUNCTIONS COMBINED

1.

a

= 3.0, b = 2.0, c = 1.0; viewpoint = (3,2,3)

1.

a

= 3.0, b = 2.0, c = 1.0; viewpoint = (3,2,3)

9.4.3. z 1.

a

9.4.4. z 1.

a

=

c COS(27Tbx) eay

= 1.0, b = 1.0, c = 0.4; viewpoint = (3, - 4,3) =

c sin(27Tbx) eay

= 1.0, b = 1.0, c = 0.4; viewpoint = (3, - 4,3)

299

9.4.1 9.4.2

9.4.3 9.4.4

300

CRC Standard Curves and Surfaces

9.5. SURFACE SPHERICAL HARMONICS For the surface harmonics, one-half of the surface is "cut away" along the (x, z) plane in order to more completely illustrate the shape of these

surfaces. The three orthogonal axes, all from -1 to + 1, are added to also clarify the illustration. 9.5.1. r = 1 + cPnO(cos cp) Zonal harmonics-Pno is the Legendre polynomial

1. 2. 3.

n = 1, c = 1.0; viewpoint = (2, - 3, 2) n = 2, c = 1.0; viewpoint = (2, - 3,2) n = 3, c = 1.0; viewpoint = (2, - 3,2)

9.5.2. r = 1 + cPnn(cos cp)cos nO Sectoral harmonics-Pnn is the associated Legendre function of the first

kind 1. 2.

3.

n = 1, c = 1; viewpoint = (2, - 3,2) viewpoint = (3, - 2,2) n = 3, c = is-; viewpoint = (3, - 2,2)

n = 2, c =

·L

9.5.3. r = 1 + c~;n(cos cp) cos me Tesseral harmonics-Pnm is the associated Legendre function of the first kind 1. 2. 3.

n = 2, m = 1, c = n = 3, m = 1, c = n = 3, m = 2, c =

t; viewpoint = t; viewpoint =

i;

(2, -3,2) (2, -3,2) viewpoint = (2, -3,2)

301 2 3

9.5.1

9.5.1

9.5.1

9.5.2

9.5.2

9.5.2

9.5.3

9.5.3

9.5.3

302

CRC Standard Curves and Surfaces

9.6. MISCELLANEOUS TRANSCENDENTAL FUNCTIONS 9.6.1. Catenoid Parametrically:

x

=

u cos u

y=usinu z 1.

=

arccosh u

1 < u < 5; 0 < u < 27T; viewpoint = (4, - 5, 1); box limits: -5 < x < 5; -5 < y < 5; -arccosh5 < z < arccosh5

9.6.2. Right Helicoid Parametrically:

x = u cos u y =

U Slll U

z = cu 1.

2. 3.

c = box c = box c = box

1/(27T); - 0.5 < u < 0.5, - 27T < u < 27T; viewpoint = (4, - 5,1); limits: -0.5 < x < 0.5, -0.5 < y < 0.5, -1 < z < 1 1/(27T); 0.0 < u < 0.5, - 27T < u < 27T; viewpoint = (4, - 5,1); limits: -0.5 < x < 0.5, -0.5 < y < 0.5, -1 < z < 1 1/(27T); 0.25 < u < 0.5, - 27T < u < 27T; viewpoint = (4, - 5,1); limits: - 0.5 < x < 0.5, - 0.5 < y < 0.5, -1 < z < 1

9.6.3. Conocuneus of Wallis Also called conical wedge Parametrically:

x

=

u cos u

y

=

u sin u

z=c(1-2cos 2 u) 1.

c = cos(7T/4); 0 < u < 1, 7T/4 < u < 37T/4; viewpoint (4,3,1); box limits: -c <x < c, 0