Licensed to: iChapters User Licensed to: iChapters User Essential Calculus Early Transcendental Functions Ron Larson The Pennsylvania State University The Behrend College Robert Hostetler The Pennsylvania State University The Behrend College Bruce H. Edwards University of Florida Houghton Mifflin Company Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Boston New York Licensed to: iChapters User Publisher: Richard Stratton Sponsoring Editor: Cathy Cantin Senior Marketing Manager: Jennifer Jones Marketing Associate: Mary Legere Development Manager: Maria Morelli Development Editor: Peter Galuardi Editorial Associate: Jeannine Lawless Supervising Editor: Karen Carter Associate Project Editor: Susan Miscio Editorial Assistant: Joanna Carter Art and Design Manager: Gary Crespo Cover Design Manager: Anne Katzeff Photo Editor: Jennifer Meyer Dare We have included examples and exercises that use real-life data as well as technology output from a variety of software. This would not have been possible without the help of many people and organizations. Our wholehearted thanks goes to all for their time and effort. Cover photograph: “Music of the Spheres” by English sculptor John Robinson is a three-foot-tall sculpture in bronze that has one continuous edge. You can trace its edge three times around before returning to the starting point. To learn more about this and other works by John Robinson, see the Centre for the Popularisation of Mathematics, University of Wales, at http://www.popmath.org.uk/sculpture/gallery2.html. Trademark Acknowledgments: TI is a registered trademark of Texas Instruments, Inc. Mathcad is a registered trademark of MathSoft, Inc. Windows, Microsoft, and MS-DOS are registered trademarks of Microsoft, Inc. Mathematica is a registered trademark of Wolfram Research, Inc. DERIVE is a registered trademark of Texas Instruments, Inc. IBM is a registered trademark of International Business Machines Corporation. Maple is a registered trademark of Waterloo Maple, Inc. HM ClassPrep is a trademark of Houghton Mifflin Company. Diploma is a registered trademark of Brownstone Research Group. Copyright © 2008 by Houghton Mifflin Company. All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, or by any information storage or retrieval system, without the prior written permission of Houghton Mifflin Company unless such copying is expressly permitted by federal copyright law. Address inquiries to College Permissions, Houghton Mifflin Company, 222 Berkeley Street, Boston, MA 02116-3764. Printed in the U.S.A. Library of Congress Control Number: 2006934184 ISBN 13: 978-0-618-87918-2 ISBN 10: 0-618-87918-8 1 2 3 4 5 6 7 8 9-DOW-11 10 09 08 07 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User Contents A Word from the Authors viii Integrated Learning System for Calculus Features xv Chapter 1 Limits and Their Properties 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Chapter 2 x I Linear Models and Rates of Change 1 Functions and Their Graphs 9 Inverse Functions 20 Exponential and Logarithmic Functions 31 Finding Limits Graphically and Numerically Evaluating Limits Analytically 48 Continuity and One-Sided Limits 58 Infinite Limits 70 Review Exercises 77 Differentiation 38 80 2.1 The Derivative and the Tangent Line Problem 80 2.2 Basic Differentiation Rules and Rates of Change 90 2.3 Product and Quotient Rules and Higher-Order Derivatives 102 2.4 The Chain Rule 112 2.5 Implicit Differentiation 126 2.6 Derivatives of Inverse Functions 134 2.7 Related Rates 140 2.8 Newton’s Method 148 Review Exercises 153 iii Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User iv CONTENTS Chapter 3 Applications of Differentiation 157 3.1 Extrema on an Interval 157 3.2 Rolle’s Theorem and the Mean Value Theorem 164 3.3 Increasing and Decreasing Functions and the First Derivative Test 170 3.4 Concavity and the Second Derivative Test 180 3.5 Limits at Infinity 187 3.6 Optimization Problems 197 3.7 Differentials 208 Review Exercises 214 Chapter 4 Integration 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 Chapter 5 217 Antiderivatives and Indefinite Integration 217 Area 227 Riemann Sums and Definite Integrals 238 The Fundamental Theorem of Calculus 248 Integration by Substitution 260 Numerical Integration 273 The Natural Logarithmic Function: Integration 279 Inverse Trigonometric Functions: Integration 287 Hyperbolic Functions 294 Review Exercises 304 Applications of Integration 5.1 5.2 5.3 5.4 5.5 5.6 306 Area of a Region Between Two Curves 306 Volume: The Disk Method 315 Volume: The Shell Method 325 Arc Length and Surfaces of Revolution 333 Applications in Physics and Engineering 343 Differential Equations: Growth and Decay 359 Review Exercises 366 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User CONTENTS Chapter 6 Integration Techniques, L’Hôpital’s Rule, and Improper Integrals 368 6.1 6.2 6.3 6.4 6.5 6.6 6.7 Chapter 7 Integration by Parts 368 Trigonometric Integrals 376 Trigonometric Substitution 384 Partial Fractions 392 Integration by Tables and Other Integration Techniques Indeterminate Forms and L’Hôpital’s Rule 405 Improper Integrals 415 Review Exercises 425 Infinite Series 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 Chapter 8 v 427 Sequences 427 Series and Convergence 438 The Integral and Comparison Tests 448 Other Convergence Tests 456 Taylor Polynomials and Approximations 466 Power Series 476 Representation of Functions by Power Series 485 Taylor and Maclaurin Series 491 Review Exercises 502 Conics, Parametric Equations, and Polar Coordinates 504 8.1 8.2 8.3 8.4 8.5 Plane Curves and Parametric Equations 504 Parametric Equations and Calculus 513 Polar Coordinates and Polar Graphs 522 Area and Arc Length in Polar Coordinates 531 Polar Equations and Conics and Kepler’s Laws 539 Review Exercises 546 Copyright 2008 Cengage Learning. 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May not be copied, scanned, or duplicated, in whole or in part. 400 Licensed to: iChapters User vi CONTENTS Chapter 9 Vectors and the Geometry of Space 9.1 9.2 9.3 9.4 9.5 9.6 9.7 Chapter 10 549 Vectors in the Plane 549 Space Coordinates and Vectors in Space 559 The Dot Product of Two Vectors 566 The Cross Product of Two Vectors in Space 574 Lines and Planes in Space 581 Surfaces in Space 592 Cylindrical and Spherical Coordinates 601 Review Exercises 607 Vector-Valued Functions 609 10.1 Vector-Valued Functions 609 10.2 Differentiation and Integration of Vector-Valued Functions 616 10.3 Velocity and Acceleration 623 10.4 Tangent Vectors and Normal Vectors 631 10.5 Arc Length and Curvature 640 Review Exercises 651 Chapter 11 Functions of Several Variables 11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8 653 Introduction to Functions of Several Variables Limits and Continuity 664 Partial Derivatives 673 Differentials and the Chain Rule 682 Directional Derivatives and Gradients 694 Tangent Planes and Normal Lines 704 Extrema of Functions of Two Variables 712 Lagrange Multipliers 720 Review Exercises 726 Copyright 2008 Cengage Learning. 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May not be copied, scanned, or duplicated, in whole or in part. 653 Licensed to: iChapters User vii CONTENTS Chapter 12 Multiple Integration 728 12.1 12.2 12.3 12.4 12.5 12.6 12.7 Iterated Integrals and Area in the Plane 728 Double Integrals and Volume 735 Change of Variables: Polar Coordinates 745 Center of Mass and Moments of Inertia 752 Surface Area 759 Triple Integrals and Applications 765 Triple Integrals in Cylindrical and Spherical Coordinates 775 12.8 Change of Variables: Jacobians 781 Review Exercises 787 Chapter 13 Vector Analysis 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 790 Vector Fields 790 Line Integrals 800 Conservative Vector Fields and Independence of Path Green’s Theorem 822 Parametric Surfaces 830 Surface Integrals 839 Divergence Theorem 850 Stokes’s Theorem 858 Review Exercises 864 Appendix A Proofs of Selected Theorems A1 Appendix B Integration Tables A17 Appendix C Business and Economic Applications Answers to Odd-Numbered Exercises Index A109 Additional Appendices A22 A29 The following appendices are available at the textbook website at college.hmco.com/pic/larsonEC. Appendix D Precalculus Review D.1 Real Numbers and the Real Number Line D.2 The Cartesian Plane D.3 Review of Trigonometric Functions Appendix E Rotation and General Second-Degree Equation Appendix F Complex Numbers Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. 813 Licensed to: iChapters User A Word from the Authors A Streamlined Text In recent years, we have heard from some users, reviewers, and colleagues that calculus books are too long and too expensive. To address these concerns, we developed a streamlined version of our calculus text. In doing so, it was important not to compromise our core philosophies: (1) to write a precise, readable book for students with the basic rules and concepts clearly defined and demonstrated; and (2) to design a comprehensive teaching instrument that employs proven pedagogical techniques, freeing the instructor to make the most efficient use of classroom time. To write Essential Calculus: Early Transcendental Functions, we asked our readers: Exactly what are the essential topics for a three-semester calculus sequence? Essential Calculus The resulting textbook is approximately 23 the size of our mainstream text. The structure and coverage of the topics enable a faster-paced course to cover the material in a mathematically sound, thorough, and rigorous manner. While developing the streamlined text, we recognized that some instructors and their students may need additional practice problems or reference materials, so we moved the following material from the text to the website college.hmco.com/pic/larson/EC: • • • • • • Fourth Edition Material on differential equations Material on conics Section projects PS Problem Solving Exercises Chapter overview application and graphics Index of Applications A Text Formed by Its Users Third Edition Much has changed since we began writing calculus textbooks in 1973—over 30 years ago. With each edition we have listened to our users, colleagues, and students and incorporated many of your suggestions for improvement. Through your support and suggestions, versions of this text have evolved over the years to include these extensive enhancements: Second Edition First Edition • Comprehensive exercise sets with a wide variety of problems such as skill-building exercises, applications, explorations, writing exercises, critical thinking exercises, theoretical problems, and problems from the Putnam Exam • Comprehensive and mathematically rigorous text • Abundant, real-life applications (many with real data) that accurately represet the diverse uses of calculus • Open-ended activities and investigations that help students develop an understanding of mathematical concepts intuitively • Clear, uncluttered text presentation with full annotations and labels and a carefully planned page layout that is designed for maximum readability • Comprehensive, four-color art program viii Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User A WORD FROM THE AUTHORS ix • Technology used throughout as both a problem-solving and an investigative tool • Comprehensive program of additional resources available in print and online • With 9 different volumes of the text available, you can choose the sequence, amount of content, and teaching approach that is best for you and your students. • References to the history of calculus and to the mathematicians who developed it • References to over 50 articles from mathematical journals available at www.MathArticles.com • Worked out solutions to the odd-numbered text exercises provided in the printed Student Study and Solutions Guide, in Eduspace, and at www.CalcChat.com Although we streamlined the text to create Essential Calculus: Early Transcendental Functions, we did not change many of the things our colleagues and the over two million students who have used other versions of the texts have told us work for them. We hope you will enjoy this text. We welcome any comments, as well as suggestions for continued improvements. Ron Larson Robert Hostetler Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Bruce H. Edwards Licensed to: iChapters User Integrated Learning System for Calculus Over 25 Years of Success, Leadership, and Innovation The best-selling authors Larson, Hostetler, and Edwards continue to offer instructors and students more flexible teaching and learning options for the calculus course. Calculus Textbook Options The early transcendental functions calculus course is available in a variety of textbook configurations to address the different ways instructors teach—and students take—their classes. CALCULUS: Early Transcendental Functions Designed for the three-semester sequence Designed for the two-semester sequence Designed for the single-semester courses CALCULUS with Late Trigonometry Designed for the three-semester sequence Designed for third semester of Calculus CALCULUS, Eighth Edition Designed for the three-semester sequence Designed for the two-semester sequence Designed for the single-semester courses Designed for third semester of Calculus x Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Designed for the foursemester precalculus with calculus sequence Licensed to: iChapters User An Integrated Learning System that makes a difference to you and your students Many more resources are available with the Larson/Hostetler/Edwards Calculus series to address your needs and the needs of your students. Integrate Graphing Calculators • Access to a COLOR graphing Calculator for all students • Graphing calculators Explorations in the textbook and additional activities in Eduspace® • Calculator programs that do routine calculus computations so students can focus on more complex problems • Graphing Calculator Guides for various calculator models Use Computer Algebra Systems: Maple™, Mathematica®, Mathcad®, and Derive® • Open Explorations in Eduspace® expand textbook examples using a Computer Algebra System (CAS) • Calculus Labs guide students to explore more complex problems using a Computer Algebra System • Download data and other materials to make it easier to integrate a CAS Teach Online • Eduspace® with online homework, tutoring, and testing resources, including SMARTHINKING™ tutoring • Instructional DVDs • CalcChat student discussion forums • Eduspace® online course management tools Your Calculus Course Present Calculus Visually • Animations and Rotatable 3D Graphs visualize concepts and enhance student understanding • Digital (PowerPoint) Figures enable you to create presentation materials using textbook artwork • Math Graphs allow students to print enlarged textbook graphs for homework Eduspace® online tutorials • Live, Smarthinking™ tutoring • Algorithmically-generated practice problems • Point-of-use video clips • Additional examples and practice problems Make Calculus Relevant • Math Articles enrich students’ understanding of calculus • Math Trends and Biographies help students see how Calculus developed over time • Simulations engage students and enable them to explore calculus concepts • Real-World Videos and Connections show how calculus concepts connect to students’ lives and fields of study The Integrated Learning System for Essential Calculus: Early Transcendental Functions, offers dynamic teaching teaching tools for instructors and interactive learning resources for students in the following flexible course delivery formats. • Eduspace® online learning system • HM Testing CD-ROM • Study and Solutions Guide in two volumes available in print and electronically • Instructional DVDs and videos • Companion Textbook Websites for students and instructors • Complete Solutions Guide (for instructors only) available only electronically xi Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User Integrated Learning System for Calculus Eduspace® Online Calculus Eduspace®, powered by Blackboard®, is ready to use and easy to integrate into the calculus course. It provides comprehensive homework exercises, tutorials, and testing keyed to the textbook by section. Features • Online Multimedia eBook interactive textbook content organized at the section level • Algorithmic Homework (Practice and Graded) based on • • • • • • • • • • • • examples from the textbook, organized at the chapter and section level; includes full Equation Editor to support free response question types Explore It First (with editable graphs) organized at the section level Video Explanations organized at the section level eSolutions (worked-out solutions to the odd-numbered textbook exercises) organized at the chapter and section level Online Color Graphing Calculator Full Test Bank content One-click access to SMARTHINKING® live, online tutoring for students Comprehensive problem sets for graded homework Ample prerequisite skills review with customized student self-study plan Chapter Tests Link to CalcChat Electronic version of all textbook exercises Tech Support available when you need it most Instructor Resources Student Resources • Algorithmically generated tutorial exercises for • Algorithmically generated tutorial questions for • • • • • • • unlimited practice Comprehensive problem sets for graded homework Electronic version of all textbook exercises Interactive (multimedia) textbook pages with video lectures, animations, and much more Symbol palette for free response questions Ample prerequisite skills review with customized student self-study plan Electronic gradebook HM Testing unlimited practice of prerequisite skills • Point-of-use links to additional tools, animations, • • • • • • • • • • and simulations Symbol palette for writing math notation SMARTHINKING® live, online tutoring Graphing calculator Customized self-study plan Chapter tests Interactive ebook 3-D rotatable graphs Prerequisite skills review exercises Video instruction which corresponds to sections of text Worked-out solutions to odd-numbered exercises For additional information about the Larson, Hostetler, and Edwards Calculus program, go to college.hmco.com/info/larsoncalculus. xii Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User This website contains an array of useful instructor resources keyed to the textbook. Features 54 Chapter 2 Differentiation Test Form A Name __________________________________________ Date Chapter 2 Class __________________________________________ Section _______________________ • Complete Solutions Guide by Bruce Edwards ____________________________ 1. If f x ⫽ 2x2 ⫹ 4, which of the following will calculate the derivative of f ? (a) 2x ⫹ ⌬x2 ⫹ 4 ⫺ 2x2 ⫹ 4 ⌬x (b) lim 2x2 ⫹ 4 ⫹ ⌬x ⫺ 2x2 ⫹ 4 ⌬x (c) lim 2x ⫹ ⌬x2 ⫹ 4 ⫺ 2x2 ⫹ 4 ⌬x ⌬x→0 ⌬x→0 (d) 2x2 ⫹ 4 ⫹ ⌬x ⫺ 2x2 ⫹ 4 ⌬x (e) None of these 2. Differentiate: y ⫽ 1 ⫹ cos x . 1 ⫺ cos x (a) ⫺1 (d) (b) ⫺2 csc x ⫺2 sin x 1 ⫺ cos x2 (c) 2 csc x (e) None of these 3. Find dydx for y ⫽ x3x ⫹ 1. 3x2 2x ⫹ 1 (b) (d) 7x ⫹ 2x ⫹ 1 (e) None of these 3 x2 (c) 3x2x ⫹ 1 4. Find f⬘x for f x ⫽ 4 ⫹ e2x. (a) e2x 4 ⫹ e2x (d) e x (b) 1 22e2x (c) xe2x⫺1 4 ⫹ e2x (e) None of these 5. The position equation for the movement of a particle is given by s ⫽ t 2 ⫺ 13 when s is measured in feet and t is measured in seconds. Find the acceleration at two seconds. (a) 342 unitssec2 (b) 18 unitssec2 (d) 90 unitssec2 (e) None of these (c) 288 unitssec2 © Houghton Mifflin Company. All rights reserved. x27x ⫹ 6 2x ⫹ 1 (a) This resource contains worked-out solutions to all textbook exercises in electronic format. • Instructor’s Resource Guide by Ann Rutledge Kraus This resource contains an abundance of resources keyed to the textbook by chapter and section, including chapter summaries, teaching strategies, multiple versions of chapter tests, final exams, and gateway tests, and suggested solutions to the Chapter Openers, Explorations, Section Projects, and Technology features in the text in electronic format. • Test Item File The Test Item File contains a sample question for every algorithm in HM Testing in electronic format. • Digital textbook art including 3-D rotatable graphs. HM Testing (powered by Diploma™) For the instructor, HM Testing is a robust test-generating system. Features • Comprehensive set of algorithmic test items • Can produce chapter tests, cumulative tests, and final exams • Online testing • Gradebook function xiii Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User Integrated Learning System for Calculus Instructional DVDs and Videos These comprehensive DVD and video presentations complement the textbook topic coverage and have a variety of uses, including supplementing an online or hybrid course, giving students the opportunity to catch up if they miss a class, and providing substantial course material for self-study and review. Features • Comprehensive topic coverage from Calculus correlated to section topics • Additional explanations of calculus concepts, sample problems, and applications Companion Textbook Website The free Houghton Mifflin website at college.hmco.com/pic/larsonEC contains an abundance of instructor and student resources. Features • Downloadable graphing calculator programs • Textbook Appendices D – F, containing additional presentations with exercises covering precalculus review, rotation and the general second-degree equation, and complex numbers • Algebra Review Summary • Calculus Labs • 3-D rotatable graphs Printed Resources For the convenience of students, the Study and Solutions Guides are available as printed supplements, but are also available in electronic format. Study and Solutions Guide by Bruce Edwards This student resource contains detailed, worked-out solutions to all odd-numbered textbook exercises. It is available in two volumes: Volume I covers Chapters 1–8 and Volume II covers Chapters 9–13. For additional information about the Larson, Hostetler, and Edwards Calculus program, go to college.hmco.com/info/larsoncalculus. xiv Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User Features Essential Calculus offers a number of proven pedagogical features developed by the Larson team to promote student mastery of Calculus. In order to streamline this version for faster paced courses, we have moved some content to online resources, leaving the essential course content presented in a variety of ways to appeal to different learning styles, instructional approaches, and course configurations. 2 Differentiation Section 2.1 The Derivative and the Tangent Line Problem • Find the slope of the tangent line to a curve at a point. • Use the limit definition to find the derivative of a function. • Understand the relationship between differentiability and continuity. The Tangent Line Problem Calculus grew out of four major problems that European mathematicians were working on during the seventeenth century. 1. The tangent line problem (this section) y 2. The velocity and acceleration problem (Sections 2.2 and 2.3) 3. The minimum and maximum problem (Section 3.1) 4. The area problem (Section 4.2) P x Tangent line to a circle Figure 2.1 E X P L O R AT I O N Integrating a Radical Function Up to this point in the text, you have not evaluated the following integral. ⫺1 1 ⫺ y y y y = f(x) FOR FURTHER INFORMATION For more information on the crediting of mathematical discoveries to the first “discoverer,” see the article “Mathematical Firsts—Who Done It?” by Richard H. Williams and Roy D. Mazzagatti in Mathematics Teacher. To view this article, go to the website www.matharticles.com. 1 x2 Each problem involves the notion of a limit, and calculus can be introduced with any of the four problems. Although partial solutions to the tangent line problem were given by Pierre de Fermat (1601–1665), René Descartes (1596–1650), Christian Huygens (1629–1695), and Isaac Barrow (1630 –1677), credit for the first general solution is usually given to Isaac Newton (1642–1727) and Gottfried Leibniz (1646–1716). Newton’s work on this problem stemmed from his interest in optics and light refraction. What does it mean to say that a line is tangent to a curve at a point? For a circle, the tangent line at a point P is the line that is perpendicular to the radial line at point P, as shown in Figure 2.1. For a general curve, however, the problem is more difficult. For example, how would you define the tangent lines shown in Figure 2.2? You might say that a line is tangent to a curve at a point P if it touches, but does not cross, the curve at point P. This definition would work for the first curve shown in Figure 2.2, but not for the second. Or you might say that a line is tangent to a curve if the line touches or intersects the curve at exactly one point. This definition would work for a circle but not for more general curves, as the third curve in Figure 2.2 shows. dx From geometry, you should be able to find the exact value of this integral— what is it? Using numerical integration with Simpson’s Rule or the Trapezoidal Rule, you can’t be sure of the accuracy of the approximation. Why? P P P x y = f (x) y = f (x) x x Tangent line to a curve at a point Figure 2.2 80 Section Openers Try finding the exact value using the substitution Every section begins with an outline of the key concepts covered in the section. This serves as a class planning resource for the instructor and a study and review guide for the student. x ⫽ sin and dx ⫽ cos d. Does your answer agree with the value you obtained using geometry? Explorations Mary Evans Picture Library For selected topics, Explorations offer the opportunity to discover calculus concepts before they are formally introduced in the text, thus enhancing student understanding. This optional feature can be omitted at the discretion of the instructor with no loss of continuity in the coverage of the material. ARCHIMEDES (287–212 B.C.) Archimedes used the method of exhaustion to derive formulas for the areas of ellipses, parabolic segments, and sectors of a spiral. He is considered to have been the greatest applied mathematician of antiquity. Historical Notes Integrated throughout the text, Historical Notes help students grasp the basic mathematical foundations of calculus. xv Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User xvi FEATURES 96 CHAPTER 2 All Theorems and Definitions are highlighted for emphasis and easy reference. Proofs are shown for selected theorems to enhance student understanding. Derivatives of Exponential Functions E X P L O R AT I O N One of the most intriguing (and useful) characteristics of the natural exponential function is that it is its own derivative. Consider the following. Use a graphing utility to graph the function f x ⫽ Theorems Differentiation Let f x ⫽ e x. e x⫹⌬x ⫺ e x ⌬x f⬘ x ⫽ lim for ⌬x ⫽ 0.01. What does this function represent? Compare this graph with that of the exponential function. What do you think the derivative of the exponential function equals? ⌬x→0 f x ⫹ ⌬ x ⫺ f x ⌬x e x⫹⌬x ⫺ e x ⫽ lim ⌬x→0 ⌬x e xe ⌬x ⫺ 1 ⫽ lim ⌬x→0 ⌬x Study Tips The definition of e Located at point of use throughout the text, Study Tips advise students on how to avoid common errors, address special cases, and expand upon theoretical concepts. lim 1 ⫹ ⌬ x1⌬x ⫽ e ⌬x→0 tells you that for small values of ⌬ x, you have e 1 ⫹ ⌬ x1⌬x, which implies that e ⌬x 1 ⫹ ⌬ x. Replacing e ⌬x by this approximation produces the following. e x e ⌬x ⫺ 1 ⌬x e x 1 ⫹ ⌬ x ⫺ 1 ⌬x→0 ⌬x e x⌬ x ⫽ lim ⌬x→0 ⌬ x ⫽ ex f⬘ x ⫽ lim STUDY TIP The key to the formula for the derivative of f x ⫽ e x is the limit lim 1 ⫹ x 1x x→0 ⌬x→0 ⫽ lim ⫽ e. This important limit was introduced on page 33 and formalized later on page 54. It is used to conclude that for ⌬x 0, 1 ⫹ ⌬x1⌬ x e. Graphics This result is stated in the next theorem. THEOREM 2.7 Numerous graphics throughout the text enhance student understanding of complex calculus concepts (especially in three-dimensional representations), as well as real-life applications. Derivative of the Natural Exponential Function d x e ⫽ e x dx y At the point (1, e), the slope is e ≈ 2.72. 4 You can interpret Theorem 2.7 graphically by saying that the slope of the graph of f x ⫽ e x at any point x, e x is equal to the y-coordinate of the point, as shown in Figure 2.20. Derivatives of Exponential Functions 3 EXAMPLE 9 2 Find the derivative of each function. a. f x ⫽ 3e f (x) = e x At the point (0, 1), the slope is 1. 1 2 b. f x ⫽ x 2 ⫹ e x c. f x ⫽ sin x ⫺ e x Solution x −2 Figure 2.20 x a. f⬘ x ⫽ 3 d x e ⫽ 3e x dx b. f⬘ x ⫽ d 2 d x ⫹ e x ⫽ 2x ⫹ e x dx dx c. f⬘ x ⫽ d d sin x ⫺ e x ⫽ cos x ⫺ e x dx dx 128 CHAPTER 2 Differentiation y Examples It is meaningless to solve for dydx in an equation that has no solution points. (For example, x 2 ⫹ y 2 ⫽ ⫺4 has no solution points.) If, however, a segment of a graph can be represented by a differentiable function, dydx will have meaning as the slope at each point on the segment. Recall that a function is not differentiable at (1) points with vertical tangents and (2) points at which the function is not continuous. 1 x2 + y2 = 0 Numerous examples enhance the usefulness of the text as a study and learning tool. The detailed, worked-out Solutions (many with side comments to clarify the steps or the method) are presented graphically, analytically, and/or numerically to provide students with opportunities for practice and further insight into calculus concepts. Many Examples incorporate real-data analysis. (0, 0) x −1 1 EXAMPLE 3 −1 a. x 2 ⫹ y 2 ⫽ 0 y 1 − x2 y= 1 (−1, 0) (1, 0) −1 −1 a. The graph of this equation is a single point. So, the equation does not define y as a differentiable function of x. b. The graph of this equation is the unit circle, centered at 0, 0. The upper semicircle is given by the differentiable function x 1 − x2 y=− y ⫽ 1 ⫺ x 2, (b) y= y ⫽ ⫺ 1 ⫺ x 2, ⫺1 < x < 1. 1−x At the points ⫺1, 0 and 1, 0, the slope of the graph is undefined. c. The upper half of this parabola is given by the differentiable function 1 x y ⫽ 1 ⫺ x, 1 −1 y=− y ⫽ ⫺ 1 ⫺ x, Some graph segments can be represented by differentiable functions. Figure 2.28 x < 1. At the point 1, 0, the slope of the graph is undefined. EXAMPLE 4 Finding the Slope of a Graph Implicitly Determine the slope of the tangent line to the graph of x 2 ⫹ 4y 2 ⫽ 4 at the point 2, ⫺12 . See Figure 2.29. y Solution 2 x 2 + 4y 2 = 4 x −1 1 −2 Figure 2.29 Instructional Notes accompany many of the Theorems, Definitions, and Examples to offer additional insights or describe generalizations. x < 1 and the lower half of this parabola is given by the differentiable function 1−x (c) Notes ⫺1 < x < 1 and the lower semicircle is given by the differentiable function y −1 Eduspace® contains Open Explorations, which investigate selected Examples using computer algebra systems (Maple, Mathematica, Derive, and Mathcad). The icon identifies these Examples. c. x ⫹ y 2 ⫽ 1 b. x 2 ⫹ y 2 ⫽ 1 Solution 1 (1, 0) Open Exploration Representing a Graph by Differentiable Functions If possible, represent y as a differentiable function of x (see Figure 2.28). (a) ( 2, − 1 2 ) x 2 ⫹ 4y 2 ⫽ 4 dy ⫽0 dx dy ⫺2x ⫺x ⫽ ⫽ dx 8y 4y 2x ⫹ 8y Write original equation. Differentiate with respect to x. Solve for dy . dx So, at 2, ⫺12 , the slope is ⫺ 2 dy 1 ⫽ ⫽ . dx ⫺42 2 Evaluate dy 1 when x ⫽ 2 and y ⫽ ⫺ . dx 2 NOTE To see the benefit of implicit differentiation, try doing Example 4 using the explicit function y ⫽ ⫺ 124 ⫺ x 2. Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User xvii FEATURES Exercises In Exercises 25 and 26, find an equation of the line that is tangent to the graph of f and parallel to the given line. The core of every calculus text, Exercises provide opportunities for exploration, practice, and comprehension. Essential Calculus contains over 7500 Section and Chapter Review Exercises, carefully graded in each set from skill-building to challenging. The extensive range of problem types includes true/false, writing, conceptual, real-data modeling, and graphical analysis. Function Line 25. f x ⫽ x 3 Putnam Exam Challenge 3x ⫺ y ⫹ 1 ⫽ 0 1 26. f x ⫽ x ⫺ 1 61. Find the maximum value of f x ⫽ x3 ⫺ 3x on the set of all real numbers x satisfying x 4 ⫹ 36 ≤ 13x2. Explain your reasoning. x ⫹ 2y ⫹ 7 ⫽ 0 62. Find the minimum value of 27. The tangent line to the graph of y ⫽ gx at the point 5, 2 In Exercises 59– 62, describe the x-values at which f is x ⫹ 1x6 ⫺ x 6 ⫹ 1x 6 ⫺ 2 9, 0 . g 5 g ⬘ 5 . passes through the point Find and differentiable. x ⫹ 1x3 ⫹ x3 ⫹ 1x3 59. f x ⫽ 1 x⫹1 for x > 0. 60. f x ⫽ x 2 ⫺ 9 These problems were composed by the Committee on the Putnam Prize Competition. © The Mathematical Association of America. All rights reserved. y y 12 10 1 6 4 2 x −2 −1 1 −4 −2 Putnam Exam Challenge 61. f x ⫽ x ⫺ 3 23 Problems from the William Lowell Putnam Mathematical Competitions, administered by the Mathematical Association of America, are included at the end of certain exercise sets to provide students with additional challenging exercises. These can be assigned as a group project or individually for more advanced students. Many professors enjoy pointing them out as an additional challenge exercise of the math concept just covered. −2 2 4 −4 65. The graph of every cubic polynomial has precisely one point of inflection. x ≤ 0 x >66.0 The graph of f x ⫽ 1x is concave downward for x < 0 and concave upward for x > 0, and thus it has a point of inflection at x ⫽ 0. x 2 ⫺ 4, 4 ⫺ x 2, 62. f x ⫽ y y 5 4 3 True or False? In Exercises 65–70, determine whether the statement is true or false. If it is false, explain why or give an x example that shows it is false. 67. The maximum value of y ⫽ 3 sin x ⫹ 2 cos x is 5. 4 g 68. The maximum slope of the graph of y ⫽ sinbx is b. 2 x −4 1 4 x 1 2 3 4 5 6 −4 122. Modeling Data The normal daily maximum temperatures T (in degrees Fahrenheit) for Denver, Colorado, are shown in the table. (Source: National Oceanic and Atmospheric Administration) Month Jan Feb Mar Apr May Jun Temperature 43.2 47.2 53.7 60.9 70.5 82.1 Month Jul Aug Sep Oct Nov Dec Temperature 88.0 86.0 77.4 66.0 51.5 44.1 (a) Use a graphing utility to plot the data and find a model for the data of the form Tt ⫽ a ⫹ b sin t6 ⫺ c where T is the temperature and t is the time in months, with t ⫽ 1 corresponding to January. (b) Use a graphing utility to graph the model. How well does the model fit the data? (c) Find T⬘ and use a graphing utility to graph the derivative. TECHNOLOGY PITFALL When using a graphing utility to graph a function involving radicals or rational exponents, be sure you understand the way the utility evaluates radical expressions. For instance, even though f x ⫽ x 2 ⫺ 423 and gx ⫽ x 2 ⫺ 4 2 13 are the same algebraically, some graphing utilities distinguish between these two functions. Which of the graphs shown in Figure 3.21 is incorrect? Why did the graphing utility produce an incorrect graph? f(x) = (x 2 − 4) 2/3 g(x) = [(x 2 − 4)2 ]1/3 5 4 −4 −1 5 4 −4 Technology Throughout the text, the use of a graphing utility or computer algebra system is suggested as appropriate for problem-solving as well as exploration and discovery. For example, students may choose to use a graphing utility to execute complicated computations, to visualize theoretical concepts, to discover alternative approaches, or to verify the results of other solution methods. However, students are not required to have access to a graphing utility to use this text effectively. In addition to describing the benefits of using technology to learn calculus, the text also addresses its possible misuse or misinterpretation. −1 Which graph is incorrect? Figure 3.21 Additional Features Additional teaching and learning resources are integrated throughout the textbook, including journal references, and Writing About Concepts exercises. Visit college.hmco.com/pic/larsonEC for even more teaching and learning resources. Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User Acknowledgments Essential Calculus: Early Transcendental Functions For their invaluable advice on Essential Calculus, we would like to thank: John Annulis, University of Arkansas at Monticello; Karline Feller, Georgia Perimeter College; Irvin R. Hentzel, Iowa State University; Matt Hudelson, Washington State University; Laura Jacyna, Northern Virginia Community College—Loudoun; Charles Lam, California State University, Bakersfield; Barbara Tozzi, Brookdale Community College; Dennis Reissig, Suffolk County Community College. We would also like to thank the many people who have helped us at various stages of this project over the years. Their encouragement, criticisms, and suggestions have been invaluable to us. Calculus Early Transcendental Functions, Fourth Edition Andre Adler, Illinois Institute of Technology; Evelyn Bailey, Oxford College of Emory University; Katherine Barringer, Central Virginia Community College; Robert Bass, Gardner-Webb University; Joy Becker, University of Wisconsin Stout; Michael Bezusko, Pima Community College; Bob Bradshaw, Ohlone College; Robert Brown, The Community College of Baltimore County (Essex Campus); Joanne Brunner, DePaul University; Minh Bui, Fullerton College; Fang Chen, Oxford College of Emory University; Alex Clark, University of North Texas; Jeff Dodd, Jacksonville State University; Daniel Drucker, Wayne State University; Pablo Echeverria, Camden County College; Angela Hare, Messiah College; Karl Havlak, Angelo State University; James Herman, Cecil Community College; Xuezhang Hou, Towson University; Gene Majors, Fullerton College; Suzanne Molnar, College of St. Catherine; Karen Murany, Oakland Community College; Keith Nabb, Moraine Valley Community College; Stephen Nicoloff, Paradise Valley Community College; James Pommersheim, Reed College; James Ralston, Hawkeye Community College; Chip Rupnow, Martin Luther College; Mark Snavely, Carthage College; Ben Zandy, Fullerton College For the Fourth Edition Technology Program Jim Ball, Indiana State University; Marcelle Bessman, Jacksonville University; Tim Chappell, Penn Valley Community College; Oiyin Pauline Chow, Harrisburg Area Community College; Julie M. Clark, Hollins University; Jim Dotzler, Nassau Community College; Murray Eisenberg, University of Massachusetts at Amherst; Arek Goetz, San Francisco State University; John Gosselin, University of Georgia; Shahryar Heydari, Piedmont College; Douglas B. Meade, University of South Carolina; Teri Murphy, University of Oklahoma; Howard Speier, Chandler-Gilbert Community College xviii Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User ACKNOWLEDGMENTS xix Reviewers of Previous Editions Raymond Badalian, Los Angeles City College; Norman A. Beirnes, University of Regina; Christopher Butler, Case Western Reserve University; Dane R. Camp, New Trier High School, IL; Jon Chollet, Towson State University; Barbara Cortzen, DePaul University; Patricia Dalton, Montgomery College; Luz M. DeAlba, Drake University; Dewey Furness, Ricks College; Javier Garza, Tarleton State University; Claire Gates, Vanier College; Lionel Geller, Dawson College; Carollyne Guidera, University College of Fraser Valley; Irvin Roy Hentzel, Iowa State University; Kathy Hoke, University of Richmond; Howard E. Holcomb, Monroe Community College; Gus Huige, University of New Brunswick; E. Sharon Jones, Towson State University; Robert Kowalczyk, University of Massachusetts–Dartmouth; Anne F. Landry, Dutchess Community College; Robert F. Lax, Louisiana State University; Beth Long, Pellissippi State Technical College; Gordon Melrose, Old Dominion University; Bryan Moran, Radford University; David C. Morency, University of Vermont; Guntram Mueller, University of Massachusetts–Lowell; Donna E. Nordstrom, Pasadena City College; Larry Norris, North Carolina State University; Mikhail Ostrovskii, Catholic University of America; Jim Paige, Wayne State College; Eleanor Palais, Belmont High School, MA; James V. Rauff, Millikin University; Lila Roberts, Georgia Southern University; David Salusbury, John Abbott College; John Santomas, Villanova University; Lynn Smith, Gloucester County College; Linda Sundbye, Metropolitan State College of Denver; Anthony Thomas, University of Wisconsin–Platteville; Robert J. Vojack, Ridgewood High School, NJ; Michael B. Ward, Bucknell University; Charles Wheeler, Montgomery College We would like to thank the staff at Larson Texts, Inc., who assisted with proofreading the manuscript, preparing and proofreading the art package, and checking and typesetting the supplements. On a personal level, we are grateful to our wives, Deanna Gilbert Larson, Eloise Hostetler, and Consuelo Edwards, for their love, patience, and support. Also, a special note of thanks goes to R. Scott O’Neil. If you have suggestions for improving this text, please feel free to write to us. Over the years we have received many useful comments from both instructors and students, and we value these very much. Ron Larson Robert Hostetler Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Bruce H. Edwards Licensed to: iChapters User Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User A Proofs of Selected Theorems THEOREM 1.2 Properties of Limits (Properties 2, 3, 4, and 5) (page 48) Let b and c be real numbers, let n be a positive integer, and let f and g be functions with the following limits. lim f x L lim g x K and x→c 2. Sum or difference: x→c lim f x ± gx L ± K x→c lim f xgx LK 3. Product: x→c f x L , provided K 0 gx K n lim f x Ln 4. Quotient: lim x→c 5. Power: x→c Proof To prove Property 2, choose > 0. Because 2 > 0, you know that there exists 1 > 0 such that 0 < x c < 1 implies f x L < 2. You also know that there exists 2 > 0 such that 0 < x c < 2 implies gx K < 2. Let be the smaller of 1 and 2; then 0 < x c < implies that f x L < and gx K < . 2 2 So, you can apply the triangle inequality to conclude that f x gx L K ≤ f x L gx K < 2 2 which implies that lim f x gx L K lim f x lim gx. x→c x→c x→c The proof that lim f x gx L K x→c is similar. To prove Property 3, given that lim f x L x→c and lim gx K x→c you can write f xgx f x L gx Lgx f x LK. Because the limit of f x is L, and the limit of gx is K, you have lim f x L 0 and x→c lim gx K 0. x→c A1 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User A2 APPENDIX A Proofs of Selected Theorems Let 0 < < 1. Then there exists > 0 such that if 0 < x c < , then f x L 0 < and gx K 0 < which implies that f x L gx K 0 f x L gx K < < . So, lim [ f x L gx K 0. x→c Furthermore, by Property 1, you have lim Lgx LK lim Kf x KL. and x→c x→c Finally, by Property 2, you obtain lim f xgx lim f x L gx K lim Lgx lim Kf x lim LK x→c x→c x→c x→c x→c 0 LK KL LK LK. To prove Property 4, note that it is sufficient to prove that lim x→c 1 1 . gx K Then you can use Property 3 to write lim x→c f x 1 1 L lim f x lim f x lim . x→c gx gx x→c gx x→c K Let > 0. Because lim gx K, there exists 1 > 0 such that if x→c K 2 0 < x c < 1, then gx K < which implies that K gx K gx ≤ gx K gx < gx 2 . K That is, for 0 < x c < 1, K < gx 2 1 2 . < gx K or Similarly, there exists a 2 > 0 such that if 0 < x c < 2, then K gx K < 2 2 . Let be the smaller of 1 and 2. For 0 < x c < , you have 1 K gx 1 1 gx K gxK K So, lim x→c 1 1 . gx K 1 K gx gx < 1 K 2 K2 . K 2 Finally, the proof of Property 5 can be obtained by a straightforward application of mathematical induction coupled with Property 3. Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User APPENDIX A THEOREM 1.4 Proofs of Selected Theorems A3 The Limit of a Function Involving a Radical (page 49) Let n be a positive integer. The following limit is valid for all c if n is odd, and is valid for c > 0 if n is even. n x n c. lim x→c Proof Consider the case for which c > 0 and n is any positive integer. For a given > 0, you need to find > 0 such that n x n c < whenever 0 < xc < which is the same as saying n n < x c < < x c < . whenever n n Assume < c, which implies that 0 < c < c. Now, let be the smaller of the two numbers n n c c n n c n and c. Then you have n n c c n n c c n n c n c THEOREM 1.5 < xc < xc < xc < n c < c n n c < c n < x n c < n x < n c < n n x n c < . < The Limit of a Composite Function (page 50) If f and g are functions such that lim gx L and lim f x f L, then x→c x→L lim f g x f lim gx f L. x→c Proof x→c For a given > 0, you must find > 0 such that f gx f L < whenever 0 < x c < . Because the limit of f x as x → L is f L, you know there exists 1 > 0 such that f u f L < whenever u L < 1. Moreover, because the limit of gx as x → c is L, you know there exists > 0 such that gx L < 1 whenever 0 < x c < . Finally, letting u gx, you have f gx f L < whenever 0 < x c < . Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User A4 APPENDIX A Proofs of Selected Theorems THEOREM 1.7 Functions That Agree at All But One Point (page 51) Let c be a real number and let f x gx for all x c in an open interval containing c. If the limit of gx as x approaches c exists, then the limit of f x also exists and lim f x lim gx. x→c x→c Proof Let L be the limit of gx as x → c. Then, for each > 0 there exists a > 0 such that f x gx in the open intervals c , c and c, c , and gx L < whenever 0 < x c < . f x L < whenever 0 < x c < . Because f x gx for all x in the open interval other than x c, it follows that So, the limit of f x as x → c is also L. THEOREM 1.8 The Squeeze Theorem (page 54) If hx ≤ f x ≤ gx for all x in an open interval containing c, except possibly at c itself, and if lim hx L lim gx x→c x→c then lim f x exists and is equal to L. x→c Proof For > 0 there exist 1 > 0 and 2 > 0 such that hx L < whenever 0 < x c < 1 gx L < whenever 0 < x c < 2. and Because hx ≤ f x ≤ gx for all x in an open interval containing c, except possibly at c itself, there exists 3 > 0 such that hx ≤ f x ≤ gx for 0 < x c < 3. Let be the smallest of 1, 2, and 3. Then, if 0 < x c < , it follows that hx L < and gx L < , which implies that < hx L < and L < hx and < gx L < gx < L . Now, because hx ≤ f x ≤ gx, it follows that L < f x < L , which implies that f x L < . Therefore, lim f x L. x→c Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User APPENDIX A THEOREM 1.14 Proofs of Selected Theorems A5 Vertical Asymptotes (page 72) Let f and g be continuous on an open interval containing c. If f c 0, gc 0, and there exists an open interval containing c such that gx 0 for all x c in the interval, then the graph of the function given by h x f x gx has a vertical asymptote at x c. Proof Consider the case for which f c > 0 and there exists b > c such that c < x < b implies gx > 0. Then, for M > 0, choose 1 such that 0 < x c < 1 implies f c 3f c < f x < 2 2 and 2 such that 0 < x c < 2 implies 0 < gx < f c . 2M Now let be the smaller of 1 and 2. Then it follows that 0 < xc < implies f x f c 2M > M. gx 2 f c So, it follows that lim x→c f x gx and the line x c is a vertical asymptote of the graph of h. Alternative Form of the Derivative (page 85) The derivative of f at c is given by f c lim x→c f x f c xc provided this limit exists. Proof The derivative of f at c is given by f c lim x→0 f c x f c . x Let x c x. Then x → c as x → 0. So, replacing c x by x, you have f c lim x→0 f c x f c f x f c lim . x→c x xc Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User A6 APPENDIX A Proofs of Selected Theorems THEOREM 2.11 The Chain Rule (page 113) If y f u is a differentiable function of u, and u gx is a differentiable function of x, then y f gx is a differentiable function of x and dy dy dx du du dx or, equivalently, d f gx f gxg x. dx Proof In Section 2.4, you let hx f gx and used the alternative form of the derivative to show that h c f gcg c, provided gx gc for values of x other than c. Now consider a more general proof. Begin by considering the derivative of f. f x f x lim x→0 x f x y lim x→0 x x For a fixed value of x, define a function x such that x0 . x0 0, y f x, x Because the limit of x as x → 0 doesn’t depend on the value of 0, you have lim x→0 x lim x→0 y f x 0 x and you can conclude that x 0, the equation is continuous at 0. Moreover, because y 0 when y x x xf x is valid whether x is zero or not. Now, by letting u gx x gx, you can use the continuity of g to conclude that lim x→0 u lim gx x gx 0 x→0 which implies that lim x→0 u 0. Finally, y u u uf u → y u u u f u, x x x and taking the limit as x → 0, you have dy du dx dx lim x→0 u du dy du f u 0 f u dx dx dx du f u dx du dy . dx du Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. x0 Licensed to: iChapters User APPENDIX A THEOREM 2.16 Proofs of Selected Theorems A7 Continuity and Differentiability of Inverse Functions (page 134) Let f be a function whose domain is an interval I. If f has an inverse, then the following statements are true. 1. If f is continuous on its domain, then f 1 is continuous on its domain. 2. If f is differentiable at c and f c 0, then f 1 is differentiable at f c. Proof To prove Property 1, you first need to define what is meant by a strictly increasing function or a strictly decreasing function. A function f is strictly increasing on an entire interval I if for any two numbers x1 and x2 in the interval, x1 < x2 implies f x1 < f x2 . The function f is strictly decreasing on the entire interval I if x1 < x2 implies f x1 > f x2 . The function f is strictly monotonic on the interval I if it is either strictly increasing or strictly decreasing. Now show that if f is continuous on I, and has an inverse, then f is strictly monotonic on I. Suppose that f were not strictly monotonic. Then there would exist numbers x1, x2, x3 in I such that x1 < x 2 < x3, but f x2 is not between f x1 and f x3. Without loss of generality, assume f x1 < f x3 < f x2. By the Intermediate Value Theorem, there exists a number x0 between x1 and x2 such that f x0 f x3. So, f is not one-to-one and cannot have an inverse. So, f must be strictly monotonic. Because f is continuous, the Intermediate Value Theorem implies that the set of values of f, f x: x , forms an interval J. Assume that a is an interior point of J. From the previous argument, f 1a is an interior point of I. Let > 0. There exists 0 < 1 < such that I1 f 1a 1, f 1a 1 I. Because f is strictly monotonic on I1, the set of values f x: x I1 forms an interval J1 J. Let > 0 such that a , a J1. Finally, if y a < , then f 1 y f 1a < 1 < . So, f 1 is continuous at a. A similar proof can be given if a is an endpoint. To prove Property 2, consider the limit f 1y f 1a ya f 1 a lim y→a where a is in the domain of f 1 and f 1a c. Because f is differentiable at c, f is continuous at c, and so is f 1 at a. So, y → a implies that x → c, and you have f 1 a lim x→c xc 1 1 1 lim . f x f c x→c f x f c f x f c f c lim x→c xc xc So, f 1 a exists, and f 1 is differentiable at f c. THEOREM 2.17 The Derivative of an Inverse Function (page 134) Let f be a function that is differentiable on an interval I. If f has an inverse function g, then g is differentiable at any x for which f gx 0. Moreover, g x 1 , f gx f gx 0. Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User A8 APPENDIX A Proofs of Selected Theorems Proof From the proof of Theorem 2.16, letting a x, you know that g is differentiable. Using the Chain Rule, differentiate both sides of the equation x f gx to obtain 1 f gx d gx. dx Because f gx 0, you can divide by this quantity to obtain d 1 gx . dx f gx Concavity Interpretation (page 180) 1. Let f be differentiable on an open interval I. If the graph of f is concave upward on I, then the graph of f lies above all of its tangent lines on I. 2. Let f be differentiable on an open interval I. If the graph of f is concave downward on I, then the graph of f lies below all of its tangent lines on I. Proof Assume that f is concave upward on I a, b. Then, f is increasing on a, b. Let c be a point in the interval I a, b. The equation of the tangent line to the graph of f at c is given by gx f c f cx c. If x is in the open interval c, b, then the directed distance from the point x, f x (on the graph of f ) to the point x, gx (on the tangent line) is given by d f x f c f cx c f x f c f cx c. Moreover, by the Mean Value Theorem, there exists a number z in c, x such that f z f x f c . xc So, you have d f x f c f cx c f zx c f cx c f z f cx c. The second factor x c is positive because c < x. Moreover, because f is increasing, it follows that the first factor f z f c is also positive. Therefore, d > 0 and you can conclude that the graph of f lies above the tangent line at x. If x is in the open interval a, c, a similar argument can be given. This proves the first statement. The proof of the second statement is similar. THEOREM 3.10 Limits at Infinity (page 188) If r is a positive rational number and c is any real number, then lim x→ c 0. xr Furthermore, if x r is defined when x < 0, then lim c 0. x→ xr Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User APPENDIX A Proof Proofs of Selected Theorems A9 Begin by proving that lim x→ 1 0. x For > 0, let M 1. Then, for x > M, you have x > M 1 < x 1 1 0 < . x So, by the definition of a limit at infinity, you can conclude that the limit of 1x as x → is 0. Now, using this result and letting r mn, you can write the following. lim x→ c c lim mn r x→ x x 1 n x c lim x→ 1 c lim x c lim n x→ 1 x m m m n x→ n 0 c 0 m The proof of the second part of the theorem is similar. THEOREM 4.2 nn 1 2 i1 n 2n 12 n i3 4. 4 i1 n c cn 1. 3. Summation Formulas (page 228) i1 n i 2 i1 2. nn 12n 1 6 n i Proof The proof of Property 1 is straightforward. By adding c to itself n times, you obtain a sum of cn. To prove Property 2, write the sum in increasing and decreasing order and add corresponding terms, as follows. n 2 3 . . . n 1 n 1 n 2 . . . 1 → → → → n 2 2 n → → n → i1 → n i 1 → i i1 i n 1 n 1 n 1 . . . n 1 n 1 i1 n terms So, n i i1 nn 1 . 2 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User A10 APPENDIX A Proofs of Selected Theorems To prove Property 3, use mathematical induction. First, if n 1, the result is true because 1 i i1 2 11 12 1 . 6 12 1 Now, assuming the result is true for n k, you can show that it is true for n k 1, as follows. k1 k i i2 i1 k 12 2 i1 kk 12k 1 k 12 6 k1 2k2 k 6k 6 6 k1 2k 3k 2 6 k 1k 22k 1 1 6 Property 4 can be proved using a similar argument with mathematical induction. THEOREM 4.8 Preservation of Inequality (page 244) 1. If f is integrable and nonnegative on the closed interval a, b, then b 0 ≤ a f x dx. 2. If f and g are integrable on the closed interval a, b and f x ≤ gx for every x in a, b, then b a Proof b f x dx ≤ a gx dx. To prove Property 1, suppose, on the contrary, that b a f x dx I < 0. Then, let a x0 < x1 < x2 < . . . < xn b be a partition of a, b, and let R n f c i1 i xi be a Riemann sum. Because f x ≥ 0, it follows that R ≥ 0. Now, for sufficiently small, you have R I < I2, which implies that n f c i1 i xi R < I I < 0 2 which is not possible. From this contradiction, you can conclude that b 0 ≤ a f x dx. Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User APPENDIX A Proofs of Selected Theorems A11 To prove Property 2 of the theorem, note that f x ≤ gx implies that gx f x ≥ 0. So, you can apply the result of Property 1 to conclude that b 0 ≤ gx f x dx a b 0 ≤ b a a b gx dx a f x dx b f x dx ≤ a THEOREM 6.3 gx dx. The Extended Mean Value Theorem (page 406) If f and g are differentiable on an open interval a, b and continuous on a, b such that g x 0 for any x in a, b, then there exists a point c in a, b such that f c f b f a . g c gb ga Proof You can assume that ga gb, because otherwise, by Rolle’s Theorem, it would follow that g x 0 for some x in a, b. Now, define hx to be hx f x f b f a gx. gb ga Then ha f a f b f a f agb f bga ga gb ga gb ga hb f b f b f a f agb f bga gb gb ga gb ga and and, by Rolle’s Theorem, there exists a point c in a, b such that h c f c f b f a g c 0 gb ga which implies that f b f a f c . g c gb ga Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User A12 APPENDIX A Proofs of Selected Theorems THEOREM 6.4 L’Hôpital’s Rule (page 406) Let f and g be functions that are differentiable on an open interval a, b containing c, except possibly at c itself. Assume that g x 0 for all x in a, b, except possibly at c itself. If the limit of f xgx as x approaches c produces the indeterminate form 00, then lim x→c f x f x lim x→c g x gx provided the limit on the right exists (or is infinite). This result also applies if the limit of f xgx as x approaches c produces any one of the indeterminate forms , , , or . You can use the Extended Mean Value Theorem to prove L’Hôpital’s Rule. Of the several different cases of this rule, the proof of only one case is illustrated. The remaining cases, where x → c and x → c, are left for you to prove. Proof Consider the case for which lim f x 0 and x→c lim gx 0. x→c Define the following new functions: Fx f x, 0, xc gx, and Gx xc 0, xc . xc For any x, c < x < b, F and G are differentiable on c, x and continuous on c, x. You can apply the Extended Mean Value Theorem to conclude that there exists a number z in c, x such that F z Fx Fc G z Gx Gc Fx Gx f z g z f x . gx Finally, by letting x approach c from the right, x → c, you have z → c because c < z < x, and lim x→c f x f z lim gx x→c g z lim f z g z lim f x . g x z→c x→c Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User APPENDIX A THEOREM 7.19 Proofs of Selected Theorems A13 Taylor’s Theorem (page 472) If a function f is differentiable through order n 1 in an interval I containing c, then, for each x in I, there exists z between x and c such that f x f c f cx c f c f nc 2 n x c . . . x c Rnx 2! n! where Rnx Proof f n1z x c n1. n 1! To find Rnx, fix x in I x c and write Rnx f x Pnx where Pnx is the nth Taylor polynomial for f x. Then let g be a function of t defined by x tn1 f nt gt f x f t f tx t . . . x tn Rnx . n! x cn1 The reason for defining g in this way is that differentiation with respect to t has a telescoping effect. For example, you have d f t f tx t f t f t f tx t dt f tx t. The result is that the derivative g t simplifies to g t x tn f n1t x tn n 1Rnx n! x cn1 for all t between c and x. Moreover, for a fixed x, gc f x Pnx Rnx f x f x 0 and gx f x f x 0 . . . 0 f x f x 0. Therefore, g satisfies the conditions of Rolle’s Theorem, and it follows that there is a number z between c and x such that g z 0. Substituting z for t in the equation for g t and then solving for Rnx, you obtain x zn f n1z x zn n 1Rnx 0 n! x cn1 f n1z Rnx x cn1. n 1! g z Finally, because gc 0, you have f nc 0 f x f c f cx c . . . x cn Rnx n! f nc f x f c f cx c . . . x cn Rnx. n! Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User A14 APPENDIX A Proofs of Selected Theorems THEOREM 7.20 Convergence of a Power Series (page 477) For a power series centered at c, precisely one of the following is true. 1. The series converges only at c. 2. There exists a real number R > 0 such that the series converges absolutely for x c < R, and diverges for x c > R. 3. The series converges absolutely for all x. The number R is the radius of convergence of the power series. If the series converges only at c, the radius of convergence is R 0, and if the series converges for all x, the radius of convergence is R . The set of all values of x for which the power series converges is the interval of convergence of the power series. Proof In order to simplify the notation, the theorem for the power series an x n centered at x 0 will be proved. The proof for a power series centered at x c follows easily. A key step in this proof uses the completeness property of the set of real numbers: If a nonempty set S of real numbers has an upper bound, then it must have a least upper bound (see page 434). It must be shown that if a power series an x n converges at x d, d 0, then it converges for all b satisfying b < d . Because an x n converges, lim an d n 0. x→ So, there exists N > 0 such that an d n < 1 for all n ≥ N. Then, for n ≥ N, an b n an b n So, for b < d , bn dn n bn dn n b a d < . n dn dn dn b < 1, which implies that d is a convergent geometric series. By the Comparison Test, the series an b n converges. Similarly, if the power series an x n diverges at x b, where b 0, then it diverges for all d satisfying d > b . If an d n converged, then the argument above would imply that an b n converged as well. Finally, to prove the theorem, suppose that neither case 1 nor case 3 is true. Then there exist points b and d such that an x n converges at b and diverges at d. Let S x: an x n converges. S is nonempty because b S. If x S, then x ≤ d , which shows that d is an upper bound for the nonempty set S. By the completeness property, S has a least upper bound, R. Now, if x > R, then xS, so an x n diverges. And if x < R, then x is not an upper bound for S, so there exists b in S satisfying b > x . Since b S, an b n converges, which implies that an x n converges. Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User APPENDIX A THEOREM 8.10 Proofs of Selected Theorems A15 Classification of Conics by Eccentricity (page 539) Let F be a fixed point ( focus) and let D be a fixed line (directrix) in the plane. Let P be another point in the plane and let e (eccentricity) be the ratio of the distance between P and F to the distance between P and D. The collection of all points P with a given eccentricity is a conic. 1. The conic is an ellipse if 0 < e < 1. 2. The conic is a parabola if e 1. 3. The conic is a hyperbola if e > 1. y P Proof If e 1, then, by definition, the conic must be a parabola. If e 1, then you can consider the focus F to lie at the origin and the directrix x d to lie to the right of the origin, as shown in Figure A.1. For the point P r, x, y, you have PF r and PQ d r cos . Given that e PF PQ , it follows that Q PF PQe r r ed r cos . By converting to rectangular coordinates and squaring each side, you obtain x 2 y 2 e2d x2 e2d 2 2dx x2. θ x F Completing the square produces x=d 2 x 1 ede Figure A.1 2 2 y2 e 2d 2 . 2 1e 1 e 22 If e < 1, this equation represents an ellipse. If e > 1, then 1 e 2 < 0, and the equation represents a hyperbola. THEOREM 11.4 Sufficient Condition for Differentiability (page 683) If f is a function of x and y, where fx and fy are continuous in an open region R, then f is differentiable on R. Proof Let S be the surface defined by z f x, y, where f, fx , and fy are continuous at x, y. Let A, B, and C be points on surface S, as shown in Figure A.2. From this figure, you can see that the change in f from point A to point C is given by z C B ∆z2 ∆z1 z f x ∆z x, y y f x, y f x x, y f x, y f x z1 z 2. A x, y y f x x, y Between A and B, y is fixed and x changes. So, by the Mean Value Theorem, there is a value x1 between x and x x such that y x (x + ∆x, y + ∆y) (x, y) (x + ∆x, y) z f x Figure A.2 x, y y f x, y z1 f x x, y f x, y fxx1, y x. Similarly, between B and C, x is fixed and y changes, and there is a value y1 between y and y y such that z2 f x x, y y f x x, y fy x Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. x, y1 y. Licensed to: iChapters User A16 APPENDIX A Proofs of Selected Theorems By combining these two results, you can write z z1 z 2 fx x1, y x fy x x, y1 y. If you define 1 and 2 as 1 fxx1, y fxx, y and 2 fy x x, y1 fyx, y it follows that z z1 z 2 1 fxx, y x 2 fy x, y y fx x, y x fy x, y y 1 x 2 y. By the continuity of fx and fy and the fact that x ≤ x1 ≤ x x and y ≤ y1 ≤ y y, it follows that 1 → 0 and 2 → 0 as x → 0 and y → 0. Therefore, by definition, f is differentiable. THEOREM 11.6 Chain Rule: One Independent Variable (page 686) Let w f x, y, where f is a differentiable function of x and y. If x gt and y h t, where g and h are differentiable functions of t, then w is a differentiable function of t, and d w w dx w dy . dt x dt y dt Proof Because g and h are differentiable functions of t, you know that both x and y approach zero as t approaches zero. Moreover, because f is a differentiable function of x and y, you know that w w w x y 1 x 2 y x y where both 1 and 2 → 0 as x, y → 0, 0. So, for t 0, x y w w x w y 1 2 t x t y t t t from which it follows that w w dx w dy dx dy dw 0 lim 0 t→0 dt t x dt y dt dt dt w dx w dy . x dt y dt Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User B Integration Tables Forms Involving un 1. 2. un du un1 C, n 1 n1 1 du ln u C u Forms Involving a bu 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. u 1 du 2 bu a ln a bu C a bu b C a u 1 du 2 ln a bu 2 a bu b a bu 1 u 1 a du 2 C, n 1, 2 a bun b n 2a bun2 n 1a bun1 u2 bu 1 du 3 2a bu a2 ln a bu a bu b 2 C u2 1 a2 du bu 2a ln a bu a bu2 b3 a bu C 2a u2 1 a2 du ln a bu a bu3 b 3 a bu 2a bu2 C 1 1 2a a2 u2 du C, a bun b 3 n 3a bun3 n 2a bun2 n 1a bun1 n 1, 2, 3 u 1 1 du ln C ua bu a a bu 1 u 1 1 1 du ln ua bu2 a a bu a a bu u 1 1 1 b du ln u 2a bu a u a a bu C C u 1 1 a 2bu 2b du 2 ln u 2a bu2 a ua bu a a bu C A17 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User A18 APPENDIX B Integration Tables Forms Involving a bu cu2, b2 4ac 2cu b 2 arctan C, 4ac b2 4ac b2 14. 1 du a bu cu2 15. u 1 du ln a bu cu 2 b 2 a bu cu 2c Forms Involving 16. 17. 18. 19. 20. 21. 22. 2cu b 1 ln 2 b 4ac 2cu b a bu un a bu du 2 una bu3 b2n 3 1 du u a bu un 1 ln a a bu a bu 2 na b2 < 4ac b2 4ac C, b2 > 4ac b2 4ac 1 du a bu cu 2 a C, a un1 a bu du a > 0 a bu 2 arctan C, a < 0 a a 1 1 a bu 2n 3b 1 du du , n 1 n1 n1 a bu an 1 u 2 u a bu a bu du 2 a bu a u 1 du u a bu a bu3 a bu du 1 an 1 un1 un u 22a bu du a bu 3b 2 2 2n 5b 2 a bu du , n 1 un1 a bu C un 2 du un a bu na a bu 2n 1b un1 du a bu Forms Involving a2 ± u2, a > 0 23. 24. 25. 1 1 u du arctan C a2 u2 a a 1 du u2 a2 27. 28. ua 1 1 du C ln a2 u2 2a u a u 1 1 du 2 2n 3 a2 ± u2n 2a n 1 a2 ± u2n1 Forms Involving 26. 1 du , n 1 a2 ± u2n1 u2 ± a2, a > 0 u2 ± a2 du 1 u u2 ± a2 ± a2 ln u 2 u2 u2 ± a2 du u2 a2 du u u2 ± a2 C 1 u2u2 ± a2 u2 ± a2 a4 ln u 8 u2 a2 a ln a u2 ± a2 C u2 a2 C u Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User APPENDIX B 29. 30. 31. 32. 33. 34. 35. 36. u2 a2 du u u2 ± a2 du u2 1 u u a 2 38. 39. 40. 41. 42. 43. 44. 45. du u2 u ± a2 du 1 a ln a u2 a2 C u 1 u u2 ± a2 a2 ln u 2 u u2 ± a2 C u2 ± a2 C a2u 1 du u2 ± a2 2 u2 ± a2 C u2 ± a2 C 1 1 u du arcsec C u u2 a2 a a 2 a 2 u C u2 ± a2 ln u u 1 du ln u u2 ± a2 ±u 1 du 2 2 C u2 ± a23 2 a u ± a2 Forms Involving 37. u2 a2 a arcsec a2 u2, a > 0 a2 u2 du 1 u u a2 u2 a2 arcsin C 2 a u2 a2 u2 du 1 u u2u2 a2 a2 u2 a4 arcsin C 8 a a2 u2 du u a2 u2 a ln a2 u2 du u2 a 1 u u2 du a2 u2 C u a2 u2 u arcsin C u a 1 u du arcsin C a2 u2 a a2 1 a ln a a2 u2 C u u2 1 u du u a2 u2 a2 arcsin C u2 2 a a2 u2 1 a2 u2 du C 2 2 a u a2u u 1 du 2 2 C a2 u23 2 a a u2 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Integration Tables A19 Licensed to: iChapters User A20 APPENDIX B Integration Tables Forms Involving sin u or cos u 46. 48. 50. 52. 54. 56. 58. sin u du cos u C 47. 1 sin2 u du u sin u cos u C 2 49. sinn u du sinn1 u cos u n 1 n n 51. sinn2 u du u sin u du sin u u cos u C un sin u du un cos u n 53. 55. un1 cos u du 1 du tan u sec u C 1 ± sin u 57. 61. 62. 63. 65. 67. 68. 69. 70. 71. 73. cos u du sin u C 1 cos2 u du u sin u cos u C 2 cosn u du cosn1 u sin u n 1 n n cosn2 u du u cos u du cos u u sin u C un cos u du un sin u n un1 sin u du 1 du cot u ± csc u C 1 ± cos u 1 du ln tan u C sin u cos u Forms Involving tan u, cot u, sec u, csc u 59. tan u du ln cos u C 60. cot u du ln sin u C sec u du ln sec u tan u C csc u du ln csc u cot u C or tan2 u du u tan u C 64. sec2 u du tan u C 66. tann u du tann1 u n1 cot n u du secn u du cot n1u n1 cot2 u du u cot u C csc2 u du cot u C cot n2 u du, n 1 cscn2 u cot u n 2 n1 n1 secn2 u du, n 1 cscn2u du, n 1 1 1 du u ± ln cos u ± sin u C 1 ± tan u 2 72. 1 du u cot u csc u C 1 ± sec u 74. tann2 u du, n 1 secn2 u tan u n 2 n1 n1 cscn u du csc u du ln csc u cot u C 1 1 du u ln sin u ± cos u C 1 ± cot u 2 1 du u tan u ± sec u C 1 ± csc u Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User APPENDIX B Forms Involving Inverse Trigonometric Functions 75. 77. 79. 80. arcsin u du u arcsin u 1 u2 C arctan u du u arctan u ln 1 u2 C arccsc u du u arccsc u ln u arcsec u du u arcsec u ln u 76. 78. 83. 85. 86. eau sin bu du eau cos bu du un1eu du a2 eau a sin bu b cos bu C b2 a2 eau a cos bu b sin bu C b2 84. Forms Involving ln u 87. 89. 90. ln u du u1 ln u C un ln u du 94. 96. 91. ln un du uln un n cosh u du sinh u C 93. sech2 u du tanh u C 95. sech u tanh u du sech u C 97. 100. du ln u u2 ± a2 u2 ± a2 C du 1 a ln a u a2 ± u2 1 du u ln1 eu C 1 eu u ln u du Forms Involving Inverse Hyperbolic Functions (in logarithmic form) 98. ueu du u 1eu C un1 1 n 1 ln u C, n 1 n 12 ln u2 du u 2 2 ln u ln u2 C 88. Forms Involving Hyperbolic Functions 92. arccot u du u arccot u ln 1 u2 C 2 82. 1 u2 C u 1 C eu du eu C uneu du uneu n arccos u du u arccos u u2 1 C Forms Involving eu 81. Integration Tables 99. u2 1 2 ln u C 4 ln un1 du sinh u du cosh u C csch2 u du coth u C csch u coth u du csch u C du au 1 C ln a2 u2 2a a u a2 ± u2 C u Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. A21 Licensed to: iChapters User A22 CHAPTER 6 C Differential Equations Business and Economic Applications Previously, you learned that one of the most common ways to measure change is with respect to time. In this section, you will study some important rates of change in economics that are not measured with respect to time. For example, economists refer to marginal profit, marginal revenue, and marginal cost as the rates of change of the profit, revenue, and cost with respect to the number of units produced or sold. Summary of Business Terms and Formulas Basic Terms x is the number of units produced (or sold). p is the price per unit. R is the total revenue from selling x units. C is the total cost of producing x units. Basic Formulas R xp C x PRC P is the total profit from selling x units. The break-even point is the number of units for which R C. C is the average cost per unit. C Marginals dR Marginal revenue extra revenue from selling one additional unit dx Marginal revenue 1 unit dC Marginal cost extra cost of producing one additional unit dx dP Marginal profit extra profit from selling one additional unit dx Extra revenue for one unit A revenue function Figure C.1 In this summary, note that marginals can be used to approximate the extra revenue, cost, or profit associated with selling or producing one additional unit. This is illustrated graphically for marginal revenue in Figure C.1. Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User APPENDIX C EXAMPLE 1 600 Marginal profit (50, 525) Using Marginals as Approximations P 0.0002x 3 10x. a. Find the marginal profit for a production level of 50 units. b. Compare this with the actual gain in profit obtained by increasing production from 50 to 51 units. (See Figure C.2.) 500 Profit (in dollars) A23 A manufacturer determines that the profit P (in dollars) derived from selling x units of an item is given by (51, 536.53) P Business and Economic Applications 400 300 Solution a. Because the profit is P 0.0002x3 10x, the marginal profit is given by the derivative 200 100 P = 0.0002 x 3 + 10x x 10 20 30 40 50 Number of units Marginal profit is the extra profit from selling one additional unit. Figure C.2 dP 0.0006x 2 10. dx When x 50, the marginal profit is dP 0.0006502 10 dx Marginal profit for x 50 $11.50. b. For x 50 and 51, the actual profits are P 0.000250 3 1050 25 50 $525.00 P 0.000251 3 1051 26.53 510 $536.53. So, the additional profit obtained by increasing the production level from 50 to 51 units is $536.53 $525.00 $11.53. Extra profit for one unit The profit function in Example 1 is unusual in that the profit continues to increase as long as the number of units sold increases. In practice, it is more common to encounter situations in which sales can be increased only by lowering the price per item. Such reductions in price ultimately cause the profit to decline. The number of units x that consumers are willing to purchase at a given price p per unit is defined as the demand function p f x. Demand function Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User A24 APPENDIX C Business and Economic Applications EXAMPLE 2 A business sells 2000 items per month at a price of $10 each. It is estimated that monthly sales will increase by 250 items for each $0.25 reduction in price. Find the demand function corresponding to this estimate. p Solution From the given estimate, x increases 250 units each time p drops $0.25 from the original cost of $10. This is described by the equation Price (in dollars) 20 x p = 12 − 1000 15 x 2000 250 10 p 100.25 12,000 1000p 5 or x 1000 2000 3000 4000 5000 Number of units p 12 A demand function p EXAMPLE 3 p 3.00 x , 1000 Demand function Finding the Marginal Revenue A fast-food restaurant has determined that the monthly demand for its hamburgers is p= 60,000 − x 20,000 p 2.50 60,000 x . 20,000 Find the increase in revenue per hamburger (marginal revenue) for monthly sales of 20,000 hamburgers. (See Figure C.4.) 2.00 1.50 1.00 Solution Because the total revenue is given by R xp, you have 0.50 x 20,000 40,000 R xp x 60,000 Number of units As the price decreases, more hamburgers are sold. Figure C.4 x ≥ 2000. The graph of the demand function is shown in Figure C.3. Figure C.3 Price (in dollars) Finding a Demand Function x 1 60,000x x ). 60,000 20,000 20,000 2 By differentiating, you can find the marginal revenue to be dR 1 60,000 2x. dx 20,000 When x 20,000, the marginal revenue is dR 1 60,000 220,000 dx 20,000 20,000 20,000 $1 per unit. NOTE The demand function in Example 3 is typical in that a high demand corresponds to a low price, as shown in Figure C.4. Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User APPENDIX C P Profit (in dollars) Suppose that in Example 3 the cost C (in dollars) of producing x hamburgers is x 2 − 5,000 20,000 C 5000 0.56x, (24,400, 24,768) 25,000 0 ≤ x ≤ 50,000. Find the total profit and the marginal profit for 20,000, 24,400, and 30,000 units. 20,000 Solution Because P R C, you can use the revenue function in Example 3 to obtain 15,000 10,000 5,000 x 20,000 −5,000 40,000 Number of units The maximum profit corresponds to the point where the marginal profit is 0. When more than 24,400 hamburgers are sold, the marginal profit is negative—increasing production beyond this point will reduce rather than increase profit. Figure C.5 1 60,000x x 2 5000 0.56x 20,000 x2 2.44x 5000. 20,000 P So, the marginal profit is dP x . 2.44 dx 10,000 The table shows the total profit and the marginal profit for each of the three indicated demands. Figure C.5 shows the graph of the profit function. Demand 20,000 24,400 30,000 Profit $23,800 $24,768 $23,200 $0.44 $0.00 $0.56 Marginal profit Finding the Maximum Profit EXAMPLE 5 3500 Profit (in dollars) A25 Finding the Marginal Profit EXAMPLE 4 P = 2.44x − Business and Economic Applications R = 50 3000 In marketing an item, a business has discovered that the demand for the item is represented by x p 2500 Maximum profit: dR = dC dx dx 2000 1500 1000 500 x 2 3 4 5 Number of units (in thousands) dR dC Maximum profit occurs when . dx dx . Demand function The cost C (in dollars) of producing x items is given by C 0.5x 500. Find the price per unit that yields a maximum profit (see Figure C.6). C = 0.5x + 500 1 50 x Solution From the given cost function, you obtain P R C xp 0.5x 500. Primary equation Substituting for p (from the demand function) produces Px Figure C.6 50x 0.5x 500 50x 0.5x 500. Setting the marginal profit equal to 0, dP 25 0.5 0 dx x yields x 2500. From this, you can conclude that the maximum profit occurs when the price is p 50 2500 50 $1.00. 50 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User A26 APPENDIX C Business and Economic Applications NOTE To find the maximum profit in Example 5, the profit function, P R C, was differentiated and set equal to 0. From the equation dP dR dC 0 dx dx dx it follows that the maximum profit occurs when the marginal revenue is equal to the marginal cost, as shown in Figure C.6. Minimizing the Average Cost EXAMPLE 6 Cost per unit (in dollars) C C= 800 x + 0.04 + 0.0002 x A company estimates that the cost C (in dollars) of producing x units of a product is given by C 800 0.04x 0.0002x 2. Find the production level that minimizes the average cost per unit. 2.00 1.50 Solution Substituting the given equation for C produces 1.00 C 0.50 x 1000 2000 3000 C 800 0.04x 0.0002x 2 800 0.04 0.0002x. x x x Setting the derivative d C dx equal to 0 yields 4000 dC 800 2 0.0002 0 dx x Number of units Minimum average cost occurs when dC 0. dx x2 800 4,000,000 ⇒ x 2000 units. 0.0002 See Figure C.7. Figure C.7 Exercises for Appendix C See www.CalcChat.com for worked-out solutions to odd-numbered exercises. 1. Think About It The figure shows the cost C of producing x units of a product. (a) What is C0 called? 3. R 900x 0.1x 2 (b) Sketch a graph of the marginal cost function. (c) Does the marginal cost function have an extremum? If so, describe what it means in economic terms. C C 4. R 600x 2 0.02x 3 5. R 1,000,000x 0.02x 2 1800 6. R 30x 2 C C In Exercises 3–6, find the number of units x that produces a maximum revenue R. 3 2x R In Exercises 7–10, find the number of units x that produces the minimum average cost per unit C. 7. C 0.125x 2 20x 5000 8. C 0.001x 3 5x 250 C(0) x Figure for 1 x Figure for 2 2. Think About It The figure shows the cost C and revenue R for producing and selling x units of a product. 9. C 3000x x 2300 x 10. C 2x 3 x 2 5000x x 2 2500 (a) Sketch a graph of the marginal revenue function. (b) Sketch a graph of the profit function. Approximate the position of the value of x for which profit is maximum. Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User APPENDIX C In Exercises 11–14, find the price per unit p (in dollars) that produces the maximum profit P. Demand Function Cost Function 11. C 100 30x p 90 x 12. C 2400x 5200 p 6000 0.4x 2 13. C 4000 40x 0.02x 2 p 50 14. C 35x 2x 1 p 40 x 1 x 100 Average Cost In Exercises 15 and 16, use the cost function to find the value of x at which the average cost is a minimum. For that value of x, show that the marginal cost and average cost are equal. 15. C 2x 2 5x 18 16. C x 3 6x 2 13x 17. Prove that the average cost is a minimum at the value of x where the average cost equals the marginal cost. 18. Maximum Profit The profit P for a company is where s is the amount (in hundreds of dollars) spent on advertising. What amount of advertising produces a maximum profit? 19. Numerical, Graphical, and Analytic Analysis The cost per unit for the production of a radio is $60. The manufacturer charges $90 per unit for orders of 100 or less. To encourage large orders, the manufacturer reduces the charge by $0.15 per radio for each unit ordered in excess of 100 (for example, there would be a charge of $87 per radio for an order size of 120). (a) Analytically complete six rows of a table such as the one below. (The first two rows are shown.) Price A27 21. Minimum Cost A power station is on one side of a river that 1 is 2 mile wide, and a factory is 6 miles downstream on the other side. It costs $12 per foot to run power lines over land and $16 per foot to run them underwater. Find the most economical path for the transmission line from the power station to the factory. 22. Maximum Revenue When a wholesaler sold a product at $25 per unit, sales were 800 units per week. After a price increase of $5, the average number of units sold dropped to 775 per week. Assume that the demand function is linear, and find the price that will maximize the total revenue. 23. Minimum Cost The ordering and transportation cost C (in thousands of dollars) of the components used in manufacturing a product is C 100 x , 200 x x 30 2 1 ≤ x where x is the order size (in hundreds). Find the order size that minimizes the cost. (Hint: Use Newton’s Method or the zero feature of a graphing utility.) 24. Average Cost A company estimates that the cost C (in dollars) of producing x units of a product is P 230 20s 12s 2 x Business and Economic Applications Profit 102 90 20.15 10290 20.15 10260 3029.40 104 90 40.15 10490 40.15 10460 3057.60 (b) Use a graphing utility to generate additional rows of the table. Use the table to estimate the maximum profit. (Hint: Use the table feature of the graphing utility.) C 800 0.4x 0.02x 2 0.0001x 3. Find the production level that minimizes the average cost per unit. (Hint: Use Newton’s Method or the zero feature of a graphing utility.) 25. Revenue The revenue R for a company selling x units is R 900x 0.1x 2. Use differentials to approximate the change in revenue if sales increase from x 3000 to x 3100 units. 26. Analytic and Graphical Analysis A manufacturer of fertilizer finds that the national sales of fertilizer roughly follow the seasonal pattern F 100,000 1 sin 2 t 60 365 (c) Write the profit P as a function of x. where F is measured in pounds. Time t is measured in days, with t 1 corresponding to January 1. (d) Use calculus to find the critical number of the function in part (c), and find the required order size. (a) Use calculus to determine the day of the year when the maximum amount of fertilizer is sold. (e) Use a graphing utility to graph the function in part (c) and verify the maximum profit from the graph. (b) Use a graphing utility to graph the function and approximate the day of the year when sales are minimum. 20. Maximum Profit A real estate office handles 50 apartment units. When the rent is $720 per month, all units are occupied. However, on the average, for each $40 increase in rent, one unit becomes vacant. Each occupied unit requires an average of $48 per month for service and repairs. What rent should be charged to obtain a maximum profit? Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User A28 CHAPTER 6 Differential Equations 27. Modeling Data The table shows the monthly sales G (in thousands of gallons) of gasoline at a gas station in 2004. The time in months is represented by t, with t 1 corresponding to January. (a) Use a graphing utility to plot the data. (b) Find a model of the form S a bt c sin t for the data. (Hint: Start by finding . Next, use a graphing utility to find a bt. Finally, approximate c.) (c) Use a graphing utility to graph the model with the data and make any adjustments necessary to obtain a better fit. t 1 2 3 4 5 6 G 8.91 9.18 9.79 9.83 10.37 10.16 (d) Use the model to predict the maximum quarterly sales in the year 2006. t 7 8 9 10 11 12 G 10.37 10.81 10.03 9.97 9.85 9.51 30. Think About It Match each graph with the function it best represents—a demand function, a revenue function, a cost function, or a profit function. Explain your reasoning. [The graphs are labeled (a), (b), (c), and (d).] A model for these data is (a) t 0.62 . G 9.90 0.64 cos 6 40,000 30,000 (a) Use a graphing utility to plot the data and graph the model. 10,000 (b) 20,000 20,000 (b) Use the model to approximate the month when gasoline sales were greatest. (c) What factor in the model causes the seasonal variation in sales of gasoline? What part of the model gives the average monthly sales of gasoline? 10,000 x x 2,000 (c) 8,000 2,000 8,000 2,000 8,000 (d) 40,000 30,000 40,000 30,000 20,000 20,000 10,000 (d) Suppose the gas station added the term 0.02t to the model. What does the inclusion of this term mean? Use this model to estimate the maximum monthly sales in the year 2008. 28. Airline Revenues The annual revenue R (in millions of dollars) for an airline for the years 1995–2004 can be modeled by 40,000 30,000 10,000 x 2,000 x 8,000 R 4.7t 4 193.5t 3 2941.7t 2 19,294.7t 52,012 Elasticity The relative responsiveness of consumers to a change in the price of an item is called the price elasticity of demand. If p f x is a differentiable demand function, the price elasticity of demand is where t 5 corresponds to 1995. (a) During which year (between 1995 and 2004) was the airline’s revenue the least? (b) During which year was the revenue the greatest? (c) Find the revenues for the years in which the revenue was least and greatest. (d) Use a graphing utility to confirm your results in parts (a) and (b). 29. Modeling Data The manager of a department store recorded the quarterly sales S (in thousands of dollars) of a new seasonal product over a period of 2 years, as shown in the table, where t is the time in quarters, with t 1 corresponding to the winter quarter of 2002. t 1 2 3 4 5 6 7 8 S 7.5 6.2 5.3 7.0 9.1 7.8 6.9 8.6 p/x . dp / dx For a given price, if < 1, the demand is inelastic, and if > 1, the demand is elastic. In Exercises 31–34, find for the demand function at the indicated x-value. Is the demand elastic, inelastic, or neither at the indicated x-value? 31. p 400 3x x 20 33. p 400 0.5x 2 x 20 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. 32. p 5 0.03x x 100 34. p 500 x2 x 23 Licensed to: iChapters User Index A B Barrow, Isaac (1630–1677), 130 Base(s) of an exponential function, 120 of a logarithmic function, 120 other than e, derivatives for, 120 Basic differentiation rules for elementary functions, 138 Basic equation, 394 guidelines for solving, 398 Basic integration rules, 219, 290 Basic limits, 48 Basic types of transformations, 13 Bearing, 556 Bernoulli, James (1654–1705), 510 Bernoulli, John (1667–1748), 392 Bifolium, 132 Binomial series, 496 Bisection method, 66 Boundary point of a region R, 664 Bounded above, 434 below, 434 monotonic sequence, 434 region R, 712 sequence, 434 Brachistochrone problem, 510 Breteuil, Emilie de (1706–1749), 344 Bullet-nose curve, 124 C Cardioid, 527, 528 Catenary, 297 Cauchy, Augustin-Louis (1789–1857), 63 Cauchy-Schwarz Inequality, 573 Center of curvature, 645 of gravity, 348 of a one-dimensional system, 347 of a two-dimensional system, 348 of mass, 347, 348, 349 of a one-dimensional system, 347 of a planar lamina, 349 of a planar lamina of variable density, 754, 770 of a two-dimensional system, 348 of a power series, 476 Centered at c, 466 Central force field, 791 Centripetal component of acceleration, 635 Centroid, 350 of a simple region, 754 A109 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. INDEX Abel, Niels Henrik (1802–1829), 151 Absolute convergence, 459 Absolute maximum of a function, 157 of two variables, 712 Absolute minimum of a function, 157 of two variables, 712 Absolute value derivative involving, 119 function, 12 Absolute Value Theorem for sequences, 431 Absolute zero, 62 Absolutely convergent, 459 Acceleration, 108, 624, 646 centripetal component of, 635 tangential and normal components of, 634, 635, 648 vector, 634, 648 Accumulation function, 254 Addition of ordinates, 295 of vectors in the plane, 551 in space, 561 Additive Identity Property of Vectors, 552 Additive Interval Property, 243 Additive Inverse Property of Vectors, 552 Agnesi, Maria Gaetana (1718–1799), 190 d'Alembert, Jean Le Rond (1717–1783), 673 Algebraic function(s), 14, 15, 137 derivatives of, 121 Algebraic properties of the cross product, 575 Alternating series, 456 geometric series, 456 harmonic series, 457, 459 remainder, 458 Alternating Series Test, 456 Alternative form of the derivative, A5 of the directional derivative, 697 of Green's Theorem, 827, 828 Angle between two nonzero vectors, 567 between two planes, 583 of inclination of a plane, 708 Angular speed, 757 Antiderivative, 217 of f with respect to x, 218 general, 218 representation of, 217 of a vector-valued function, 620 Antidifferentiation, 218 of a composite function, 260 Aphelion, 545 Approximating zeros bisection method, 66 Intermediate Value Theorem, 65 with Newton's Method, 148 Approximation linear, 208, 684 tangent line, 208 Arc length, 333, 334 function, 641 parameter, 641, 642 in parametric form, 516 of a polar curve, 535 of a space curve, 640 in the xy-plane, 760 Arccosecant function, 24, 25 Arccosine function, 24, 25 Arccotangent function, 24, 25 Archimedes (287–212 B.C.), 229 Arcsecant function, 24, 25 Arcsine function, 24, 25 series for, 497 Arctangent function, 24, 25 series for, 497 Area line integral for, 825 of a parametric surface, 834 in polar coordinates, 531 of a rectangle, 229 of a region between two curves, 307 of a region in the plane, 233, 730 of a surface of revolution, 338 in parametric form, 517 in polar coordinates, 536 of the surface S, 760 in the xy-plane, 760 Associative Property of Vector Addition, 552 Astroid, 132 Asymptote(s) horizontal, 188 slant, 193 vertical, 71, 72, A5 Average rate of change, 3 Average value of a continuous function over a solid region Q, 774 of a function on an interval, 252 of a function over a region R, 744 Average velocity, 97 Axis of revolution, 315 Licensed to: iChapters User A110 INDEX Chain Rule, 112, 113, 121, A6 implicit differentiation, 690 one independent variable, 686, A16 and trigonometric functions, 117 two independent variables, 688 Change in x, 81 Change in y, 81 Change of variables, 263 for definite integrals, 266 for double integrals, 783 guidelines for making, 264 to polar form, 747 using a Jacobian, 781 Charles’s Law, 62 Circle, 132, 528 Circle of curvature, 645 Circulation of F around C, 861 Circumscribed rectangle, 231 Cissoid, 132 Classification of conics by eccentricity, 539, A15 Closed curve, 818 disk, 664 region R, 664 surface, 850 Cobb-Douglas production function, 658 Coefficient, 14 leading, 14 Collinear, 8 Common types of behavior associated with nonexistence of a limit, 41 Commutative Property of the dot product, 566 of vector addition, 552 Comparison Test Direct, 451 Limit, 452 Complete, 434 Completeness, 65 Completing the square, 288 Component of acceleration centripetal, 635 normal, 635, 648 tangential, 635, 648 Component form of a vector in the plane, 550 Component functions, 609 Components of a vector, 570 along v, 570 in the direction of v, 571 orthogonal to v, 570 in the plane, 550 Composite function, 15 antidifferentiation of, 260 continuity of, 63 limit of, 50, A3 of two variables, 654 continuity of, 669 Composition of functions, 15 Concave downward, 180 Concave upward, 180 Concavity, 180 interpretation, A8 test for, 181 Conditional convergence, 459 Conditionally convergent, 459 Conic(s) classification by eccentricity, 539, A15 directrix of, 539 eccentricity of, 539 focus of, 539 polar equations of, 540 Connected region, 816 Conservative vector field, 793, 813 independence of path, 816 test for, 794, 796 Constant force, 343 function, 14 of integration, 218 Multiple Rule, 93, 121 differential form, 211 of proportionality, 360 Rule, 90, 121 term of a polynomial function, 14 Constraint, 720 Continuity of a composite function, 63 of a composite function of two variables, 669 differentiability implies, 87, 685 and differentiability of inverse functions, 134, A7 implies integrability, 240 properties of, 63 of a vector-valued function, 613 Continuous, 58 at c, 48, 58 on the closed interval a, b, 61 everywhere, 58 function of two variables, 668 on an interval, 613 from the left and from the right, 61 on an open interval a, b, 58 in the open region R, 668, 670 at a point, 613 x0 , y0, 668 x0 , y0, z 0, 670 vector field, 790 Continuously differentiable, 333 Contour lines, 656 Converge, 150, 428, 438 Convergence absolute, 459 conditional, 459 of a geometric series, 440 of improper integral with infinite discontinuities, 418 of improper integral with infinite integration limits, 415 interval of, 477, 481 of p-series, 449 of a power series, 477, A14 radius of, 477, 481 of a sequence, 428 of a series, 438 of Taylor series, 493 tests for series Alternating Series Test, 456 Direct Comparison Test, 451 geometric series, 440 guidelines, 463 Integral Test, 448 Limit Comparison Test, 452 p-series, 449 Ratio Test, 461 Root Test, 462 Convergent series, nth term of, 442 Convex limaçon, 528 Coordinate conversion, 523 cylindrical to rectangular, 601 cylindrical to spherical, 604 rectangular to cylindrical, 601 rectangular to spherical, 604 spherical to cylindrical, 604 spherical to rectangular, 604 Coordinate planes, 559 xy-plane, 559 xz-plane, 559 yz-plane, 559 Coordinate system cylindrical, 601 polar, 522 spherical, 604 three-dimensional, 559 Coordinates, polar, 522 Cosecant function derivative of, 106, 121 integral of, 284 inverse of, 24, 25 Cosine function, 12 derivative of, 95, 121 integral of, 284 inverse of, 24, 25 series for, 497 Cotangent function derivative of, 106, 121 integral of, 284 inverse of, 24, 25 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User INDEX D Decomposition of NxDx into partial fractions, 393 Decreasing function, 170 test for, 170 Definite integral(s), 240 as the area of a region, 241 change of variables, 266 evaluation of a line integral as a, 802 properties of, 244 two special, 243 of a vector-valued function, 620 Degree of a polynomial function, 14 Delta, , 664 -neighborhood, 664 Demand, 8 Density, 349 Density function , 752, 770 Dependent variable, 9 of a function of two variables, 653 Derivative(s) of algebraic functions, 121 alternative form, A5 for bases other than e, 120, 121 Chain Rule, 112, 113, 121 implicit differentiation, 690 one independent variable, 686, A16 and trigonometric functions, 117 two independent variables, 688 Constant Multiple Rule, 93, 121 Constant Rule, 90, 121 of cosecant function, 106, 121 of cosine function, 95, 121 of cotangent function, 106, 121 Difference Rule, 94, 121 directional, 694, 695, 701 of an exponential function, base a, 120, 121 of a function, 83 General Power Rule, 114, 121 higher-order, 108 of hyperbolic functions, 296 implicit, 127 of an inverse function, 134, A7 of inverse trigonometric functions, 136 involving absolute value, 119 from the left and from the right, 85 of a logarithmic function, base a, 120, 121 of the natural exponential function, 96, 121 of the natural logarithmic function, 118, 121 notation, 83 parametric form, 513 partial, 673 first, 673 Power Rule, 91, 121 of power series, 481 Product Rule, 102, 121 Quotient Rule, 104, 121 of secant function, 106, 121 second, 108 Simple Power Rule, 91, 121 of sine function, 95, 121 Sum Rule, 94, 121 of tangent function, 106, 121 third, 108 of trigonometric functions, 106, 121 of a vector-valued function, 616 properties of, 618 Determinant form of cross product, 574 Difference quotient, 10, 81 Difference Rule, 94, 121 differential form, 211 Difference of two vectors, 551 Differentiability implies continuity, 87, 685 of a function of two variables, 685 Differentiable at x, 83 Differentiable, continuously, 333 Differentiable function on the closed interval a, b, 85 on an open interval a, b, 83 in a region R, 683 of three variables, 684 of two variables, 683 vector-valued, 616 Differential, 209 function of three variables, 684 function of two variables, 682 of x, 209 of y, 209 Differential equation, 218 general solution of, 218 initial condition, 222 particular solution of, 222 solutions of general, 218 particular, 222 Differential form, 211 of a line integral, 808 Differential formulas, 211 constant multiple, 211 product, 211 quotient, 211 sum or difference, 211 Differential operator, 796, 798 Laplacian, 799 Differentiation, 83 implicit, 126 Chain Rule, 690 guidelines for, 127 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. INDEX Coulomb's Law, 344, 791 Critical number(s) of a function, 159 relative extrema occur only at, 159 Critical point of a function of two variables, 713 relative extrema occur at, 713 Cross product of two vectors in space, 574 algebraic properties of, 575 determinant form, 574 geometric properties of, 576 torque, 578 Cruciform, 132 Cubic function, 14 Cubing function, 12 Curl of a vector field, 795 and divergence, 798 Curtate cycloid, 512 Curvature, 643 center of, 645 circle of, 645 formulas for, 644, 648 radius of, 645 in rectangular coordinates, 645, 648 related to acceleration and speed, 646 Curve closed, 818 lateral surface area over, 811 level, 656 orientation of, 800 piecewise smooth, 509, 800 plane, 504, 609 pursuit, 299, 301 rectifiable, 333 rose, 525, 528 simple, 822 smooth, 333, 509, 618, 631 piecewise, 509, 800 space, 609 tangent line to, 632 Cusps, 618 Cycloid, 509 curtate, 512 prolate, 515 Cylinder, 592 directrix of, 592 equations of, 592 generating curve of, 592 right, 592 rulings of, 592 Cylindrical coordinate system, 601 pole of, 601 Cylindrical coordinates converting to rectangular coordinates, 601 converting to spherical coordinates, 604 Cylindrical surface, 592 A111 Licensed to: iChapters User A112 INDEX involving inverse hyperbolic functions, 300 logarithmic, 131 numerical, 87 partial, 673 of a vector-valued function, 617 Differentiation rules Chain, 112, 113, 117, 118 Constant, 90, 121 Constant Multiple, 93, 121 cosecant function, 106, 121 cosine function, 95, 121 cotangent function, 106, 121 Difference, 94, 121 for elementary functions, 138 general, 121 General Power, 114, 121 Power, 91, 121 Product, 102, 121 Quotient, 104, 121 secant function, 106, 121 Simple Power, 91, 121 sine function, 95, 121 Sum, 94, 121 summary of, 121 tangent function, 106, 121 Dimpled limaçon, 528 Direct Comparison Test, 451 Direct substitution, 48, 49 Directed line segment, 549 equivalent, 549 initial point of, 549 length of, 549 magnitude of, 549 terminal point of, 549 Direction angles of a vector, 569 Direction cosines of a vector, 569 Direction field, 225 Direction of motion, 623 Direction numbers, 581 Direction vector, 581 Directional derivative, 694, 695 alternative form, 697 of f in the direction of u, 695, 701 of a function of three variables, 701 Directrix of a conic, 539 of a cylinder, 592 Dirichlet, Peter Gustav (1805–1859), 41 Dirichlet function, 41 Discontinuity, 59 infinite, 415 nonremovable, 59 removable, 59 Disk, 315, 664 closed, 664 method, 316 open, 664 Distance between a point and a line in space, 587 between a point and a plane, 586 Distance Formula in space, 560 Distributive Property for the dot product, 566 for vectors, 552 Diverge, 428, 438 Divergence of improper integral with infinite discontinuities, 418 of improper integral with infinite integration limits, 415 of a sequence, 428 of a series, 438 tests for series Direct Comparison Test, 451 geometric series, 440 guidelines, 463 Integral Test, 448 Limit Comparison Test, 452 nth-Term Test, 442 p-series, 449 Ratio Test, 461 Root Test, 462 of a vector field, 797 and curl, 798 Divergence-free vector field, 797 Divergence Theorem, 828, 850 Divide out common factors, 52 Domain of a function, 9 of two variables, 653 of a vector-valued function, 610 Dot product Commutative Property of, 566 Distributive Property for, 566 form of work, 572 projection using the, 571 properties of, 566 of vectors, 566 Double integral, 735, 736, 737 change of variables for, 783 of f over R, 737 properties of, 737 Doyle Log Rule, 663 Dummy variable, 242 Dyne, 343 E e, the number, 33 Eccentricity, 539 classification of conics by, 539, A15 Electric force field, 791 Elementary function(s), 14, 137 basic differentiation rules for, 138 power series for, 497 Eliminating the parameter, 506 Ellipse, 539 rotated, 132 Ellipsoid, 593, 594 Elliptic cone, 593, 595 Elliptic paraboloid, 593, 595 Endpoint extrema, 157 Energy kinetic, 819 potential, 819 Epicycloid, 512, 516 Epsilon-delta, -, 42 definition of limit, 42 Equal vectors in the plane, 550 in space, 561 Equality of mixed partial derivatives, 678 Equation of a plane in space general form, 582 standard form, 582 Equation(s) basic, 394 of cylinders, 592 guidelines for solving, 398 harmonic, 799 Laplace’s, 799 of a line general form, 5 horizontal, 5 point-slope form, 2, 5 slope-intercept form, 4, 5 in space, parametric, 581 in space, symmetric, 581 summary, 5 vertical, 5 parametric, 504, 830 primary, 197, 198 related-rate, 140 secondary, 198 of tangent plane, 705 Equilibrium, 347 Equipotential lines, 656 Equivalent conditions, 818 directed line segments, 549 Error in approximating a Taylor polynomial, 472 in measurement, 210 percent error, 210 propagated error, 210 relative error, 210 in Simpson’s Rule, 277 in Trapezoidal Rule, 277 Euler, Leonhard (1707–1783), 14 Evaluate a function, 9 Evaluating a flux integral, 845 Evaluating a surface integral, 839 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User INDEX F Factorial, 430 Family of functions, 240 Famous curves astroid, 132 bifolium, 132 bullet-nose curve, 124 circle, 132, 528 cissoid, 132 cruciform, 132 folium of Descartes, 132, 538 kappa curve, 130, 132 lemniscate, 129, 132, 528 parabola, 132 rotated ellipse, 132 rotated hyperbola, 132 serpentine, 110 top half of circle, 124 witch of Agnesi, 110, 132, 190 Faraday, Michael (1791–1867), 819 Fermat, Pierre de (1601–1665), 159 Field central force, 791 electric force, 791 force, 790 gravitational, 791 inverse square, 791 vector, 790 over Q, 790 over R, 790 velocity, 790, 791 Finite Fourier series, 383 First Derivative Test, 172 First moments, 756, 770 First partial derivatives, 673 notation for, 674 Fixed plane, 650 Fluid force, 353, 354 Fluid pressure, 353 Flux integral evaluating, 845 of F across S, 845 Focus of a conic, 539 Folium of Descartes, 132, 538 Force, 343 constant, 343 exerted by a fluid, 353, 354 of friction, 647 resultant, 555 variable, 343, 344 Force field, 790 central, 791 electric, 791 work, 805 Form of a convergent power series, 491 Formulas for curvature, 644, 648 summation, 228, A9 Fourier, Joseph (1768–1830), 485 Fourier Sine Series, 375 Friction, 647 Fubini’s Theorem, 739 for a triple integral, 766 Function, 9 absolute maximum of, 157 absolute minimum of, 157 absolute value, 12 accumulation, 254 addition of, 15 algebraic, 137 antiderivative of, 217 arc length, 333, 334, 641 average value of, 252 Cobb-Douglas production, 658 component, 609 composite, 15 of two variables, 654 composition of, 15 concave downward, 180 concave upward, 180 constant, 14 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. continuous, 58 continuously differentiable, 333 cosine, 12 critical number of, 159 cubic, 14 cubing, 12 decreasing, 170 test for, 170 defined by power series, properties of, 481 density, 752, 770 derivative of, 83 difference of, 15 Dirichlet, 41 domain of, 9 elementary, 14, 137 algebraic, 14, 15 exponential, 14 logarithmic, 14 trigonometric, 14 evaluate, 9 even, 16 explicit form, 9, 126 exponential to base a, 31, 120 extrema of, 157 extreme values of, 157 family of, 240 greatest integer, 60 harmonic, 821 hyperbolic, 294 cosecant, 294 cosine, 294 cotangent, 294 secant, 294 sine, 294 tangent, 294 identity, 12 implicit form, 9 implicitly defined, 126 increasing, 170 test for, 170 inner product of, 383 integrable, 240 inverse, 20 inverse hyperbolic, 298 cosecant, 298 cosine, 298 cotangent, 298 secant, 298 sine, 298 tangent, 298 inverse trigonometric, 24 cosecant, 24 cosine, 24 cotangent, 24 secant, 24 sine, 24 tangent, 24 INDEX Evaluation by iterated integrals, 766 Evaluation of a line integral as a definite integral, 802 Even function, 16 integration of, 268 test for, 16 Everywhere continuous, 58 Existence of an inverse function, 22 Existence of a limit, 61 Existence theorem, 65, 157 Expanded about c, 466 Explicit form of a function, 9, 126 Exponential decay, 360 Exponential function, 14, 31 to base a, 31, 120 derivative of, 120, 121 derivative of, 96, 121 properties of, 31 series for, 497 Exponential growth, 360 Exponential growth and decay model, 360 initial value, 360 proportionality constant, 360 Exponents, properties of, 31 Extended Mean Value Theorem, 406, A11 Extrema endpoint, 157 of a function, 157 guidelines for finding, 160 relative, 158 Extreme Value Theorem, 157, 712 Extreme values of a function, 157 A113 Licensed to: iChapters User A114 INDEX limit of, 38 linear, 14 logarithmic to base a, 120 logistic, 191 natural exponential, 33 natural logarithmic, 33, 34 notation, 9 odd, 16 one-to-one, 11 onto, 11 orthogonal, 383 point of inflection, 182, 183 polynomial, 14, 49 of two variables, 654 position, 97, 628 potential, 793 product of, 15 quadratic, 14 quotient of, 15 radius, 597 range of, 9 rational, 12, 15 of two variables, 654 real-valued, 9 relative extrema of, 159 relative maximum of, 158 relative minimum of, 158 Riemann zeta, 455 signum, 69 sine, 12 square root, 12 squaring, 12 step, 60 strictly monotonic, 171 of three variables continuity of, 670 directional derivative, 701 gradient of, 701 transcendental, 15, 137 transformation of a graph of, 13 horizontal shift, 13 reflection about origin, 13 reflection about x-axis, 13 reflection about y-axis, 13 reflection in the line y x, 21 vertical shift, 13 of two variables, 653 absolute maximum of, 712 absolute minimum of, 712 continuity of, 668 critical point of, 713 dependent variable, 653 differentiability implies continuity, 685 differentiable, 683 differential of, 682 domain of, 653 gradient of, 696 graph of, 655 independent variables, 653 limit of, 665 maximum of, 712 minimum of, 712 nonremovable discontinuity of, 668 partial derivative of, 673 range of, 653 relative extrema of, 712 relative maximum of, 712, 715 relative minimum of, 712, 715 removable discontinuity of, 668 total differential of, 682 vector-valued, 609 Vertical Line Test, 12 of x and y, 653 zero of, 16 Functions that agree at all but one point, 51, A4 Fundamental Theorem of Algebra, 850 of Calculus, 248 guidelines for using, 249 Second, 255 of Line Integrals, 813, 814 G Gabriel’s Horn, 421, 832 Galilei, Galileo (1564–1642), 137 Galois, Evariste (1811–1832), 151 Gauss, Carl Friedrich (1777–1855), 850 Gauss’s Law, 847 Gauss’s Theorem, 850 General antiderivative, 218 General differentiation rules, 121 General form of the equation of a line, 5 of the equation of a plane in space, 582 General harmonic series, 449 General Power Rule for differentiation, 114, 121 for integration, 265 General solution of a differential equation, 218 Generating curve of a cylinder, 592 Geometric properties of the cross product, 576 Geometric property of triple scalar product, 579 Geometric series, 440 alternating, 456 convergence of, 440 Gibbs, Josiah Willard (1839–1903), 800 Golden ratio, 437 Grad, 696 Gradient, 790, 793 of a function of three variables, 701 of a function of two variables, 696 normal to level curves, 700 normal to level surfaces, 709 properties of, 698 recovering a function from, 797 Graph(s) of absolute value function, 12 of basic functions, 12 of cosine function, 12 of cubing function, 12 of a function transformation of, 13 of two variables, 655 of identity function, 12 intercept of, 4 of parametric equations, 504 of rational function, 12 of sine function, 12 of square root function, 12 of squaring function, 12 Gravitational field, 791 Greatest integer function, 60 Green, George (1793–1841), 823 Green’s Theorem, 822 alternative forms, 827, 828 Gregory, James (1638–1675), 481 Guidelines for evaluating integrals involving secant and tangent, 379 for evaluating integrals involving sine and cosine, 376 for finding extrema on a closed interval, 160 for finding intervals on which a function is increasing or decreasing, 171 for finding an inverse function, 22 for finding limits at infinity of rational functions, 190 for finding a Taylor series, 495 for implicit differentiation, 127 for integration, 282 for integration by parts, 368 for making a change of variables, 264 for solving applied minimum and maximum problems, 198 for solving the basic equation, 398 for solving related-rate problems, 141 for testing a series for convergence or divergence, 463 for using the Fundamental Theorem of Calculus, 249 Gyration, radius of, 757 H Half-life, 361 Hamilton, Isaac William Rowan (1805–1865), 551 Harmonic equation, 799 Harmonic function, 821 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User INDEX I Identities, hyperbolic, 295, 296 Identity function, 12 Image of x under f, 9 Implicit derivative, 127 Implicit differentiation, 126, 690 Chain Rule, 690 guidelines for, 127 Implicit form of a function, 9 Implicitly defined function, 126 Improper integral, 415 convergence of, 418 divergence of, 418 with infinite discontinuities, 418 with infinite integration limits, 415 special type, 421 Inclination, angle of, 708 Incompressible, 797, 855 Increasing function, 170 test for, 170 Increment of z, 682 Increments of x and y, 682 Indefinite integral, 218 of a vector-valued function, 620 Indefinite integration, 218 Independence of path and conservative vector fields, 816 Independent of path, 816 Independent variable, 9 of a function of two variables, 653 Indeterminate form, 52, 72, 189, 405 Index of summation, 227 Inductive reasoning, 432 Inequality Cauchy-Schwarz, 573 preservation of, 244, A10 triangle, 554 Inertia moment of, 756, 770 polar, 756 Infinite discontinuity, 415 Infinite interval, 187 Infinite limit(s), 70 at infinity, 193 from the left and from the right, 70 properties of, 74 Infinite series (or series), 438 alternating, 456 convergence of, 438 divergence of, 438 geometric, 440 harmonic, alternating, 457, 459 nth partial sum, 438 properties of, 442 p-series, 449 sum of, 438 telescoping, 439 terms of, 438 Infinity, limit at, 187, 188, A8 Inflection point, 182, 183 Initial condition, 222 Initial point of a directed line segment, 549 Initial value, 360 Inner partition, 735, 765 polar, 746 Inner product of two functions, 383 of two vectors, 566 Inner radius of a solid of revolution, 318 Inscribed rectangle, 231 Inside limits of integration, 729 Instantaneous rate of change, 3 Integrability and continuity, 240 Integrable function, 240, 737 Integral(s) definite, 240 properties of, 244 two special, 243 double, 735, 736, 737 flux, 845 of hyperbolic functions, 296 improper, 415 indefinite, 218 involving inverse trigonometric functions, 287 involving secant and tangent, guidelines for evaluating, 379 involving sine and cosine, guidelines for evaluating, 376 iterated, 729 line, 801 Mean Value Theorem, 251 of px Ax 2 Bx C, 275 single, 737 of the six basic trigonometric functions, 284 surface, 839 triple, 765 Integral Test, 448 Integration additive interval property, 243 basic rules of, 219, 290 change of variables, 263 constant of, 218 of even and odd functions, 268 guidelines for, 282 indefinite, 218 involving inverse hyperbolic functions, 300 Log Rule, 279 lower limit of, 240 of power series, 481 preservation of inequality, 244, A10 region R of, 729 upper limit of, 240 of a vector-valued function, 620 Integration by parts, 368 guidelines for, 368 summary of common integrals using, 373 tabular method, 373 Integration by tables, 400 Integration formulas reduction formulas, 402 special, 388 summary of, 862 Integration rules basic, 290 General Power Rule, 265 Integration techniques integration by parts, 368 method of partial fractions, 392 substitution for rational functions of sine and cosine, 403 tables, 400 trigonometric substitution, 384 Intercept(s), 4 x-intercept, 16 y-intercept, 4 Interior point of a region R, 664, 670 Intermediate Value Theorem, 65 Interpretation of concavity, A8 Copyright 2008 Cengage Learning. 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INDEX Harmonic series, 449 alternating, 457, 459 general, 449 Helix, 610 Higher-order derivative, 108 Hooke’s Law, 344 Horizontal asymptote, 188 Horizontal component of a vector, 554 Horizontal line, 14 Horizontal Line Test, 22 Horizontal shift of a graph of a function, 13 to the left, 13 to the right, 13 Horizontally simple region of integration, 730 Huygens, Christian (1629–1695), 333 Hyperbola, 539 rotated, 132 Hyperbolic functions, 294 derivatives of, 296 graph of, addition of ordinates, 295 identities, 295, 296 integrals of, 296 inverse, 298 differentiation involving, 300 integration involving, 300 Hyperbolic identities, 295, 296 Hyperbolic paraboloid, 593, 595 Hyperboloid of one sheet, 593, 594 of two sheets, 593, 594 A115 Licensed to: iChapters User A116 INDEX Interval of convergence, 477, 481 infinite, 187 Inverse function, 20 continuity and differentiability of, 134, A7 derivative of, 134, A7 existence of, 22 guidelines for finding, 22 Horizontal Line Test, 22 reflective property of, 21 Inverse hyperbolic functions, 298 differentiation involving, 300 graphs of, 299 integration involving, 300 Inverse square field, 791 Inverse trigonometric functions, 24 derivatives of, 136 graphs of, 25 integrals involving, 287 properties of, 26 Irrotational vector field, 795 Isobars, 656 Isothermal surface, 659 Isotherms, 656 Iterated integral, 729 evaluation by, 766 inside limits of integration, 729 outside limits of integration, 729 Iteration, 148 ith term of a sum, 227 J Jacobi, Carl Gustav (1804–1851), 781 Jacobian, 781 K Kappa curve, 130, 132 Kepler, Johannes (1571–1630), 542 Kepler’s Laws, 542 Kinetic energy, 819 Kovalevsky, Sonya (1850–1891), 664 L Lagrange, Joseph-Louis (1736–1813), 166, 721 Lagrange form of the remainder, 472 Lagrange multiplier, 720, 721 Lagrange’s Theorem, 721 Lambert, Johann Heinrich (1728–1777), 294 Lamina, planar, 349 Laplace, Pierre Simon de (1749–1827), 775 Laplace’s equation, 799 Laplacian, 799 Lateral surface area over a curve, 811 Law of Conservation of Energy, 819 Leading coefficient of a polynomial function, 14 test, 14 Least upper bound, 434 Left-handed orientation, 559 Leibniz, Gottfried Wilhelm (1646–1716), 211 Leibniz notation, 211 Lemniscate, 129, 132, 528 Length of an arc, 333, 334 of a directed line segment, 549 of the moment arm, 346 of a scalar multiple, 553 of a vector in the plane, 550 of a vector in space, 561 on x-axis, 760 Level curve, 656 gradient is normal to, 700 Level surface, 658 gradient is normal to, 709 L’Hôpital, Guillaume (1661–1704), 406 L’Hôpital’s Rule, 406, A12 Limaçon, 528 convex, 528 dimpled, 528 with inner loop, 528 Limit(s), 38, 39 basic, 48 of a composite function, 50, A3 definition of, 42 - definition of, 42 evaluating direct substitution, 48, 49 divide out common factors, 52 rationalize the numerator, 52 existence of, 61 of a function involving a radical, 49, A3 of a function of two variables, 665 indeterminate form, 52, 72 infinite, 70 from the left and from the right, 70 properties of, 74 at infinity, 187, 188, A8 infinite, 193 of a rational function, guidelines for finding, 190 of integration inside, 729 lower, 240 outside, 729 upper, 240 involving e, 33, 54 from the left, 60 of the lower and upper sums, 233 nonexistence of, common types of behavior, 41 of nth term of a convergent series, 442 one-sided, 60 from the left, 60 from the right, 60 of polynomial and rational functions, 49 properties of, 48, A1 from the right, 60 of a sequence, 428 properties of, 429 strategy for finding, 51 three special, 54 of transcendental functions, 50 of trigonometric functions, 50 of a vector-valued function, 612 Limit Comparison Test, 452 Line(s) contour, 656 equation of general form, 5 horizontal, 5 point-slope form, 2, 5 slope-intercept form, 4, 5 summary, 5 vertical, 5 equipotential, 656 moment about, 346 normal, 704, 705 at a point, 133 parallel, 5 perpendicular, 5 secant, 81 slope of, 1 in space direction number of, 581 direction vector of, 581 parametric equations of, 581 symmetric equations of, 581 tangent, 81 with slope m, 81 vertical, 83 Line of impact, 704 Line integral, 801 for area, 825 differential form of, 808 evaluation of as a definite integral, 802 of f along C, 801 independent of path, 816 summary of, 848 of a vector field, 805 Line segment, directed, 549 Linear approximation, 208, 684 Linear combination, 554 Linear function, 14 Log Rule for Integration, 279 Logarithmic differentiation, 131 Logarithmic function, 14 to base a, 120 natural, 33, 34 derivative of, 118 properties of, 34 Copyright 2008 Cengage Learning. 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Licensed to: iChapters User INDEX of inertia, 756, 770 polar, 756 for a space curve, 812 of mass, 754 of a one-dimensional system, 347 of a planar lamina, 349 second, 756, 770 of a two-dimensional system, 348 Monotonic sequence, 433 bounded, 434 M Macintyre, Sheila Scott (1910–1960), 376 Maclaurin, Colin (1698–1746), 491 Maclaurin polynomial, 468 Maclaurin series, 492 Magnitude of a directed line segment, 549 of a vector in the plane, 550 Mass, 346, 845 center of, 347, 348, 349 of a planar lamina of variable density, 754, 770 two-dimensional system, 348 moments of, 754 of a planar lamina of variable density, 752 Maximum absolute, 157 of f on I, 157 of a function of two variables, 712 relative, 158 Mean Value Theorem, 166 Extended, 406, A11 for Integrals, 251 Method of Lagrange Multipliers, 720, 721 Method of partial fractions, 392 basic equation, 394 guidelines for solving, 398 Midpoint Rule, 237 in space, 560 Minimum absolute, 157 of f on I, 157 of a function of two variables, 712 relative, 158 Mixed partial derivatives, 677 equality of, 678 Möbius Strip, 838 Moment(s) about a line, 346 about the origin, 346, 347 about a point, 346 about the x-axis, 348 about the x- and y-axes, 349 about the y-axis, 348 arm, length of, 346 first, 756, 770 of a force about a point, 578 N n factorial, 430 Napier, John (1550–1617), 119 Natural exponential function, 33 derivative of, 96, 121 series for, 497 Natural logarithmic function, 33, 34 derivative of, 118 graph of, 34 properties of, 34 series for, 497 Negative of a vector, 551 Newton, Isaac (1642–1727), 81 Newton’s Law of Cooling, 363 Newton’s Law of Gravitation, 791 Newton’s Law of Universal Gravitation, 344 Newton’s Method, 148 for approximating the zeros of a function, 148 convergence of, 150 iteration, 148 Newton’s Second Law of Motion, 627 Nodes, 618 Noether, Emmy (1882–1935), 553 Nonexistence of a limit, common types of behavior, 41 Nonremovable discontinuity, 59 of a function of two variables, 668 Norm of a partition, 239, 735, 746, 765 polar, 746 of a vector in the plane, 550 Normal component of acceleration, 634, 635, 648 of a vector field, 845 Normal line, 704, 705 at a point, 133 to S at P, 705 Normal vectors, 568 principal unit, 632, 648 to a smooth parametric surface, 833 Normalization of v, 553 Notation derivative, 83 for first partial derivatives, 674 function, 9 Leibniz, 211 sigma, 227 nth Maclaurin polynomial for f at c, 468 nth partial sum, 438 nth Taylor polynomial for f at c, 468 nth term of a convergent series, 442 of a sequence, 427 nth-Term Test for Divergence, 442 Number, critical, 159 Number e, 33 limit involving, 33, 54 Numerical differentiation, 87 O Octants, 559 Odd function, 16 integration of, 268 test for, 16 Ohm’s Law, 213 One-dimensional system center of mass of, 347 moment of, 347 One-sided limit, 60 One-to-one function, 11 Onto function, 11 Open disk, 664 Open interval continuous on, 58 differentiable on, 83 Open region R, 664, 670 continuous in, 668, 670 Open sphere, 670 Operations with power series, 487 Orientable surface, 844 Orientation of a curve, 800 of a plane curve, 505 of a space curve, 609 Oriented surface, 844 Origin moment about, 346, 347 of a polar coordinate system, 522 reflection about, 13 Orthogonal, 383 graphs, 133 vectors, 568 Outer radius of a solid of revolution, 318 Outside limits of integration, 729 P Pappus Second Theorem of, 357 Theorem of, 352 Parabola, 132, 539 Parabolic spandrel, 357 Copyright 2008 Cengage Learning. 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INDEX Logarithmic properties, 35 Logarithmic spiral, 538 Logistic function, 191 Lower bound of a sequence, 434 Lower bound of summation, 227 Lower limit of integration, 240 Lower sum, 231 limit of, 233 A117 Licensed to: iChapters User A118 INDEX Parallel lines, 5 planes, 583 vectors, 562 Parameter, 504 arc length, 641, 642 eliminating, 506 Parametric equations, 504 graph of, 504 of a line in space, 581 for a surface, 830 Parametric form of arc length, 516 of area of a surface of revolution, 517 of the derivative, 513 Parametric surface, 830 area of, 834 equations for, 830 partial derivatives of, 833 smooth, 833 normal vector to, 833 surface area of, 834 Partial derivative(s), 673 equality of mixed, 678 first, 673 of a function of two variables, 673 mixed, 677 notation for, 674 of a parametric surface, 833 of r, 833 Partial differentiation, 673 Partial fractions, 392 decomposition of NxDx into, 393 method of, 392 Partial sums, sequence of, 438 Particular solution of a differential equation, 222 Partition inner, 735, 765 polar, 746 norm of, 239, 735, 765 polar, 746 regular, 239 Pascal, Blaise (1623–1662), 353 Pascal’s Principle, 353 Path, 665, 800 Percent error, 210 Perihelion, 545 Perpendicular lines, 5 planes, 583 vectors, 568 Piecewise smooth curve, 509, 800 Planar lamina, 349 center of mass of, 349 moment of, 349 Plane angle of inclination of, 708 distance between a point and, 586 region, simply connected, 822 tangent, 705 equation of, 705 vector in, 549 Plane curve, 504, 609 orientation of, 505 smooth, 800 Plane in space angle between two, 583 equation of general form, 582 standard form, 582 parallel, 583 to the axis, 585 to the coordinate plane, 585 perpendicular, 583 trace of, 585 Point of diminishing returns, 207 of inflection, 182, 183 moment about, 346 in a vector field incompressible, 855 sink, 855 source, 855 Point-slope equation of a line, 2, 5 Polar axis, 522 Polar coordinate system, 522 origin of, 522 polar axis of, 522 pole of, 522 Polar coordinates, 522 area in, 531 area of a surface of revolution in, 536 converting to rectangular coordinates, 523 Polar curve, arc length of, 535 Polar equations of conics, 540 Polar form of slope, 526 Polar moment of inertia, 756 Polar sectors, 745 Pole, 522 of cylindrical coordinate system, 601 tangent lines at, 527 Polynomial Maclaurin, 468 Taylor, 468 Polynomial approximation, 466 centered at c, 466 expanded about c, 466 Polynomial function, 14, 49 constant term of, 14 degree, 14 leading coefficient of, 14 limit of, 49 of two variables, 654 Position function, 97 for a projectile, 628 Potential energy, 819 Potential function for a vector field, 793 Power Rule for differentiation, 91, 121 for integration, 265 Power series, 476 centered at c, 476 convergence of, 477, A14 convergent form, 491 derivative of, 481 for elementary functions, 497 integration of, 481 interval of convergence of, 477 operations with, 487 properties of functions defined by, 481 interval of convergence of, 481 radius of convergence of, 481 radius of convergence of, 477 Preservation of inequality, 244, A10 Pressure, 353 fluid, 353 Primary equation, 197, 198 Principal unit normal vector, 632, 648 Probability density function, 423 Product Rule, 102, 121 differential form, 211 Projectile, position function for, 628 Projection form of work, 572 Projection of u onto v, 570 using the dot product, 571 Prolate cycloid, 515 Propagated error, 210 Properties of continuity, 63 of the cross product algebraic, 575 geometric, 576 of definite integrals, 244 of the derivative of a vector-valued function, 618 of the dot product, 566 of double integrals, 737 of exponential functions, 32 of exponents, 31 of functions defined by power series, 481 of the gradient, 698 of infinite limits, 74 of infinite series, 442 of inverse trigonometric functions, 26 of limits, 48, A1 of limits of sequences, 429 logarithmic, 35 of the natural logarithmic function, 34 of vector operations, 552 Proportionality constant, 360 p-series, 449 convergence of, 449 harmonic, 449 Pursuit curve, 299, 301 Copyright 2008 Cengage Learning. 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Licensed to: iChapters User INDEX Q R Radial lines, 522 Radical, limit of a function involving a, 49, A3 Radius of convergence, 477, 481 of curvature, 645 function, 597 of gyration, 757 Ramanujan, Srinivasa (1887–1920), 488 Range of a function, 9 of two variables, 653 Raphson, Joseph (1648–1715), 148 Rate of change, 3, 676 average, 3 instantaneous, 3 Ratio, 3 Ratio Test, 461 Rational function, 12, 15 guidelines for finding limits at infinity of, 190 limit of, 49 of two variables, 654 Rationalize the numerator, 52 Real-valued function f of a real variable x, 9 Recovering a function from its gradient, 797 Rectangle area of, 229 circumscribed, 231 inscribed, 231 representative, 306 Rectangular coordinates converting to cylindrical coordinates, 601 converting to polar coordinates, 523 converting to spherical coordinates, 604 curvature in, 645, 648 Rectifiable curve, 333 Recursively defined sequence, 427 Remainder alternating series, 458 of a Taylor polynomial, 472 Lagrange form, 472 Removable discontinuity, 59 of a function of two variables, 668 Representation of antiderivatives, 217 Representative element, 311 disk, 315 rectangle, 306 washer, 318 Resultant force, 555 Resultant vector, 551 Revolution axis of, 315 solid of, 315 surface of, 337 area of, 338 Riemann, Georg Friedrich Bernhard (1826–1866), 239 Riemann sum, 239 Riemann zeta function, 455 Right cylinder, 592 Right-handed orientation, 559 Rolle, Michel (1652–1719), 164 Rolle’s Theorem, 164 Root Test, 462 Rose curve, 525, 528 Rotated ellipse, 132 Rotated hyperbola, 132 Rotation of F about N, 861 r-simple region of integration, 747 Rule(s) basic integration, 219 Midpoint, 237 Simpson’s, 276 Trapezoidal, 274 Rulings of a cylinder, 592 S Saddle point, 715 Scalar, 549 field, 656 multiple, 551 multiplication, 551, 561 product of two vectors, 566 quantity, 549 Secant function derivative of, 106, 121 integral of, 284 inverse of, 24 Secant line, 81 Second derivative, 108 Second Derivative Test, 184 Second Fundamental Theorem of Calculus, 255 Second moment, 756, 770 Second Partials Test, 715 Copyright 2008 Cengage Learning. 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INDEX Quadratic function, 14 Quadric surface, 593 ellipsoid, 593, 594 elliptic cone, 593, 595 elliptic paraboloid, 593, 595 hyperbolic paraboloid, 593, 595 hyperboloid of one sheet, 593, 594 hyperboloid of two sheets, 593, 594 standard form of the equations of, 593, 594, 595 Quaternions, 551 Quotient, difference, 10, 81 Quotient Rule, 104, 121 differential form, 211 Reduction formulas, 402 Reflection about the origin, 13 about the x-axis, 13 about the y-axis, 13 in the line y x, 21 Reflective property of inverse functions, 21 Refraction, 206, 725 Region of integration R, 729 horizontally simple, 730 r-simple, 747 -simple, 747 vertically simple, 730 Region in the plane area of, 233, 730 between two curves, 307 centroid of, 350 connected, 816 Region R boundary point of, 664 bounded, 712 closed, 664 differentiable in, 683 interior point of, 664, 670 open, 664, 670 continuous in, 668, 670 simply connected, 822 Regular partition, 239 Related-rate equation, 140 Related-rate problems, guidelines for solving, 141 Relation, 9 Relationship between divergence and curl, 798 Relative error, 210 Relative extrema First Derivative Test for, 172 of a function, 158 of two variables, 712 occur only at critical numbers, 159 occur only at critical points, 713 Second Derivative Test for, 184 Second Partials Test for, 715 Relative maximum at c, f c, 158 First Derivative Test for, 172 of a function, 158 of two variables, 712, 715 Second Derivative Test for, 184 Second Partials Test for, 715 Relative minimum at c, f c, 158 First Derivative Test for, 172 of a function, 158 of two variables, 712, 715 Second Derivative Test for, 184 Second Partials Test for, 715 A119 Licensed to: iChapters User A120 INDEX Second Theorem of Pappus, 357 Secondary equation, 198 Separation of variables, 359 Sequence, 427 Absolute Value Theorem, 431 bounded, 434 bounded above, 434 bounded below, 434 convergence of, 428 divergence of, 428 least upper bound of, 434 limit of, 428 properties of, 429 lower bound of, 434 monotonic, 433 nth term of, 427 of partial sums, 438 recursively defined, 427 Squeeze Theorem, 430 terms of, 427 upper bound of, 434 Series, 438 absolutely convergent, 459 alternating, 456 binomial, 496 conditionally convergent, 459 convergence of, 438 divergence of, 438 nth-term test for, 442 geometric, 440 alternating, 456 convergence of, 440 guidelines for testing for convergence or divergence, 463 harmonic, alternating, 457, 459 infinite, 438 properties of, 442 Maclaurin, 492 nth partial sum, 438 nth term of convergent, 442 power, 476 p-series, 449 sum of, 438 Taylor, 491, 492 telescoping, 439 terms of, 438 Serpentine, 110 Shell method, 325, 326 Shift of a graph horizontal, 13 to the left, 13 to the right, 13 vertical, 13 downward, 13 upward, 13 Sigma notation, 227 index of summation, 227 ith term, 227 lower bound of summation, 227 upper bound of summation, 227 Signum function, 69 Simple curve, 822 Simple Power Rule, 91, 121 Simple solid region, 851 Simply connected plane region, 822 Simpson’s Rule, 276 error in, 277 Sine function, 12 derivative of, 95, 121 integral of, 284 inverse of, 24 series for, 497 Single integral, 737 Sink, 855 Slant asymptote, 193 Slope(s) field, 225, 269 of the graph of f at x c, 81 of a line, 1 in polar form, 526 of the surface in the x- and y-directions, 674 of a tangent line, 81 Slope-intercept equation of a line, 4, 5 Smooth curve, 333, 509, 618, 631 on an open interval, 618 piecewise, 509, 800 parametric surface, 833 plane curve, 800 space curve, 800 Snell’s Law of Refraction, 206, 725 Solenoidal, 797 Solid of revolution, 315 inner radius of, 318 outer radius, 318 Solid region, simple, 851 Solution general of a differential equation, 218 of an equation, by radicals, 151 by radicals, 151 Some basic limits, 48 Somerville, Mary Fairfax (1780–1872), 653 Source, 855 Space curve, 609 arc length of, 640 moment of inertia for, 812 smooth, 800 Special integration formulas, 388 Special polar graphs, 528 Special type of improper integral, 421 Speed, 98, 623, 624, 646, 648 angular, 757 Sphere, 560 open, 670 standard equation of, 560 Spherical coordinate system, 604 converting to cylindrical coordinates, 604 converting to rectangular coordinates, 604 Spiral of Archimedes, 517, 524, 538 logarithmic, 538 Square root function, 12 Squaring function, 12 Squeeze Theorem, 54, A4 for Sequences, 430 Standard equation of a sphere, 560 Standard form of the equation of a plane in space, 582 of the equations of quadric surfaces, 593, 594, 595 Standard position of a vector, 550 Standard unit vector, 554 notation, 561 Step function, 60 Stokes, George Gabriel (1819–1903), 858 Stokes’s Theorem, 827, 858 Strategy for finding limits, 51 Strictly monotonic function, 171 Substitution for rational functions of sine and cosine, 403 Sufficient condition for differentiability, 683, A15 Sum ith term of, 227 lower, 231 limit of, 233 Riemann, 239 Rule, 94, 121 differential form, 211 of a series, 438 of two vectors, 551 upper, 231 limit of, 233 Summary of common integrals using integration by parts, 373 of differentiation rules, 121 of equations of lines, 5 of integration formulas, 862 of line and surface integrals, 848 of velocity, acceleration, and curvature, 648 Summation formulas, 228, A9 index of, 227 lower bound of, 227 upper bound of, 227 Surface closed, 850 cylindrical, 592 isothermal, 659 level, 658 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User INDEX T Tables, integration by, 400 Tabular method for integration by parts, 373 Tangent function derivative of, 106, 121 integral of, 284 inverse of, 24 Tangent line(s), 81 approximation, 208 to a curve, 632 at the pole, 527 problem, 80 slope of, 81 with slope m, 81 vertical, 83 Tangent plane, 705 equation of, 705 to S at P, 705 Tangent vector, 623 Tangential component of acceleration, 634, 635, 648 Tautochrone problem, 510 Taylor, Brook (1685-1731), 468 Taylor polynomial, 468 error in approximating, 472 remainder, Lagrange form of, 472 Taylor series, 491, 492 convergence of, 493 guidelines for finding, 495 Taylor’s Theorem, 472, A13 Telescoping series, 439 Terminal point of a directed line segment, 549 Terms of a sequence, 427 of a series, 438 Test(s) for concavity, 181 conservative vector field in the plane, 794 conservative vector field in space, 796 for convergence Alternating Series Test, 456 Direct Comparison Test, 451 geometric series, 440 guidelines, 463 Integral Test, 448 Limit Comparison Test, 452 p-series, 449 Ratio Test, 461 Root Test, 462 for even and odd functions, 16 for increasing and decreasing functions, 170 Theorem, existence, 157 Theorem of Pappus, 352 second, 357 Theta, simple region of integration, 747 Third derivative, 108 Three-dimensional coordinate system, 559 left-handed orientation, 559 right-handed orientation, 559 Top half of circle, 124 Topographic map, 656 Torque, 348, 578 Total differential, 682 Total mass of a one-dimensional system, 347 of a two-dimensional system, 348 Trace of a plane in space, 585 of a surface, 593 Tractrix, 299, 300 Transcendental function, 15, 137 limits of, 50 Transformation, 13, 782 Transformation of a graph of a function, 13 basic types, 13 horizontal shift, 13 reflection about origin, 13 reflection about x-axis, 13 reflection about y-axis, 13 reflection in the line y x, 21 vertical shift, 13 Trapezoidal Rule, 274 error in, 277 Triangle inequality, 554 Trigonometric function(s), 14 cosine, 12 derivative of, 106, 117, 121 integrals of the six basic, 284 inverse, 24 derivatives of, 136 integrals involving, 287 properties of, 26 limit of, 50 sine, 12 Trigonometric substitution, 384 Triple integral, 765 of f over Q, 765 Triple scalar product, 578 geometric property of, 579 Two-dimensional system center of mass of, 348 moment of, 348 Two special definite integrals, 243 U Unit tangent vector, 631, 648 Unit vector, 550 in the direction of v in the plane, 553 in space, 561 standard, 554 Upper bound least, 434 of a sequence, 434 of summation, 227 Upper limit of integration, 240 Upper sum, 231 limit of, 233 u-substitution, 260 V Value of f at x, 9 Variable dependent, 9 dummy, 242 force, 343, 344 independent, 9 Vector(s) acceleration, 634, 648 addition associative property of, 552 commutative property of, 552 in the plane, 549 in space, 561 Additive Identity Property, 552 Additive Inverse Property of, 552 angle between two, 567 component of u along v, 570 of u orthogonal to v, 570 component form of, 550 components, 550, 570 cross product of, 574 difference of two, 551 direction, 581 direction angles of, 569 direction cosines of, 569 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. INDEX orientable, 844 oriented, 844 parametric, 830 parametric equations for, 830 quadric, 593 trace of, 593 Surface area of a parametric surface, 834 of a solid, 759, 760 Surface integral, 839 evaluating, 839 of f over S, 839 summary of, 848 Surface of revolution, 337, 597, 598 area of, 338 parametric form, 517 polar form, 536 Symmetric equations of a line in space, 581 A121 Licensed to: iChapters User A122 INDEX Distributive Property, 552 dot product of, 566 equal, 550, 561 horizontal component of, 554 initial point, 549 inner product of, 566 length of, 550, 561 linear combination of, 554 magnitude of, 550 negative of, 551 norm of, 550 normal, 568 normalization of, 553 operations, properties of, 552 orthogonal, 568 parallel, 562 perpendicular, 568 in the plane, 549 principal unit normal, 632, 648 product of two vectors in space, 574 projection of, 570 resultant, 551 scalar multiplication, 551 scalar product of, 566 in space, 561 space, 553 axioms, 553 standard position, 550 standard unit notation, 561 sum, 551 tangent, 623 terminal point, 549 triple scalar product, 578 unit, 550 in the direction of v, 553, 561 standard, 554 unit tangent, 631, 648 velocity, 623, 648 vertical component of, 554 zero, 550, 561 Vector field, 790 circulation of, 861 conservative, 793, 813 continuous, 790 curl of, 795 divergence of, 797 divergence-free, 797 incompressible, 855 irrotational, 795 line integral of, 805 normal component of, 845 over Q, 790 over R, 790 potential function for, 793 rotation of, 861 sink, 855 source, 855 solenoidal, 797 test for, 794, 796 Vector-valued function(s), 609 antiderivative of, 620 continuity of, 613 continuous on an interval, 613 continuous at a point, 613 definite integral of, 620 derivative of, 616 properties of, 618 differentiation, 617 domain of, 610 indefinite integral of, 620 integration of, 620 limit of, 612 Velocity, 98, 624 average, 97 field, 790, 791 incompressible, 797 vector, 623, 648 Vertéré, 190 Vertical asymptote, 71, 72, A5 Vertical component of a vector, 554 Vertical line, 5 Vertical Line Test, 12 Vertical shift of a graph of a function, 13 downward, 13 upward, 13 Vertical tangent line, 83 Vertically simple region of integration, 730 Volume of a solid disk method, 316 with known cross sections, 320 shell method, 325, 326 washer method, 318 Volume of a solid region, 737, 765 W Wallis, John (1616–1703), 378 Wallis’s Formulas, 378 Washer, 318 Washer method, 318 Weierstrass, Karl (1815–1897), 713 Witch of Agnesi, 110, 132, 190 Work, 572 done by a constant force, 343 done by a variable force, 343, 344 dot product form, 572 force field, 805 projection form, 572 X x-axis moment about, 348 reflection about, 13 x-intercept, 16 xy-plane, 559 xz-plane, 559 Y y-axis moment about, 348 reflection about, 13 y-intercept, 4 yz-plane, 559 Z Zero factorial, 430 Zero of a function, 16 approximating bisection method, 66 Intermediate Value Theorem, 65 with Newton’s Method, 148 Zero vector in the plane, 550 in space, 561 Copyright 2008 Cengage Learning. 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Licensed to: iChapters User DERIVATIVES AND INTEGRALS Basic Differentiation Rules 1. 4. 7. 10. 13. 16. 19. 22. 25. 28. 31. 34. d cu cu dx d u vu uv dx v v2 d x 1 dx d u e eu u dx d sin u cos uu dx d cot u csc2 uu dx u d arcsin u dx 1 u2 d u arccot u dx 1 u2 d sinh u cosh uu dx d coth u csch2 uu dx d u sinh1 u dx u2 1 d u coth1 u dx 1 u2 2. 5. 8. 11. 14. 17. 20. 23. 26. 29. 32. 35. d u ± v u ± v dx d c 0 dx d u u u , u 0 dx u d u loga u dx ln au d cos u sin uu dx d sec u sec u tan uu dx d u arccos u dx 1 u2 d u arcsec u dx u u2 1 d cosh u sinh uu dx d sech u sech u tanh uu dx d u cosh1 u dx u2 1 d u sech1 u dx u1 u2 3. 6. 9. 12. 15. 18. 21. 24. 27. 30. 33. 36. d uv uv vu dx d n u nu n1u dx d u ln u dx u d u a ln aau u dx d tan u sec2 uu dx d csc u csc u cot uu dx u d arctan u dx 1 u2 d u arccsc u dx u u2 1 d tanh u sech2 uu dx d csch u csch u coth uu dx d u tanh1 u dx 1 u2 d u csch1 u dx u 1 u2 Basic Integration Formulas 1. kf u du k f u du 2. f u ± gu du 3. du u C 4. au du 5. eu du eu C 6. sin u du cos u C 7. cos u du sin u C 8. tan u du ln cos u C 9. cot u du ln sin u C f u du ± 1 au C ln a 10. sec u du ln sec u tan u C 11. csc u du ln csc u cot u C 12. sec2 u du tan u C 13. csc2 u du cot u C 14. sec u tan u du sec u C 15. csc u cot u du csc u C 16. 17. du 1 u arctan C a 2 u2 a a 18. du u C a du u 1 arcsec C a uu2 a2 a a2 u2 arcsin Copyright 2008 Cengage Learning. 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May not be copied, scanned, or duplicated, in whole or in part. gu du Licensed to: iChapters User TRIGONOMETRY Definition of the Six Trigonometric Functions Opposite Right triangle definitions, where 0 < < 2. opp hyp sin csc e s u hyp opp en pot Hy adj hyp cos sec θ hyp adj Adjacent opp adj tan cot adj opp Circular function definitions, where is any angle. y r y sin csc r = x2 + y2 r y (x, y) x r r cos sec θ y r x x y x x cot tan x y Reciprocal Identities 1 sin x csc x 1 csc x sin x sin x cos x cot x 1 tan x cot x 1 cot x tan x cos x sin x (−1, 0) π 180° 210° x 330° (− 23 , − 12) 76π 5π 225°240° 300°315°7π 116π ( 23 , − 21) (− 22 , − 22 ) 4 43π 270° 32π 53π 4 ( 22 , − 22 ) 1 3 (0, −1) ( 2 , − 2 ) (− 12 , − 23 ) sin 2u 2 sin u cos u cos 2u cos2 u sin2 u 2 cos2 u 1 1 2 sin2 u 2 tan u tan 2u 1 tan2 u Power-Reducing Formulas 1 cos 2u 2 1 cos 2u 2 cos u 2 1 cos 2u tan2 u 1 cos 2u 1 cot2 x csc2 x Cofunction Identities Sum-to-Product Formulas x cos x cos x sin x 2 2 csc x sec x tan x cot x 2 2 x csc x cot x tan x sec 2 2 sin u sin v 2 sin sin Reduction Formulas sinx sin x cscx csc x secx sec x 0° 0 360° 2π (1, 0) sin2 u Pythagorean Identities sin2 x cos2 x 1 1 tan2 x sec2 x (− 12 , 23 ) π (0, 1) ( 12 , 23 ) 90° (− 22 , 22 ) 3π 23π 2 π3 π ( 22 , 22 ) 120° 60° 4 π 45° ( 23 , 21) (− 23 , 12) 56π 4150°135° 6 30° Double -Angle Formulas 1 sec x cos x 1 cos x sec x Tangent and Cotangent Identities tan x y cosx cos x tanx tan x cotx cot x Sum and Difference Formulas sinu ± v sin u cos v ± cos u sin v cosu ± v cos u cos v sin u sin v tan u ± tan v tanu ± v 1 tan u tan v uv uv cos 2 2 uv uv sin u sin v 2 cos sin 2 2 uv uv cos u cos v 2 cos cos 2 2 uv uv cos u cos v 2 sin sin 2 2 Product-to-Sum Formulas 1 sin u sin v cosu v cosu v 2 1 cos u cos v cosu v cosu v 2 1 sin u cos v sinu v sinu v 2 1 cos u sin v sinu v sinu v 2 Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Licensed to: iChapters User ALGEBRA Factors and Zeros of Polynomials Let px an x n an1x n1 . . . a1x a0 be a polynomial. If pa 0, then a is a zero of the polynomial and a solution of the equation px 0. Furthermore, x a is a factor of the polynomial. Fundamental Theorem of Algebra An nth degree polynomial has n (not necessarily distinct) zeros. Although all of these zeros may be imaginary, a real polynomial of odd degree must have at least one real zero. Quadratic Formula If px ax 2 bx c, and 0 ≤ b2 4ac, then the real zeros of p are x b ± b2 4ac2a. Special Factors x 2 a 2 x ax a x 3 a 3 x ax 2 ax a 2 x 3 a3 x ax 2 ax a 2 x 4 a 4 x 2 a 2x 2 a 2 Binomial Theorem x y2 x 2 2xy y 2 x y2 x 2 2xy y 2 x y3 x 3 3x 2y 3xy 2 y 3 x y3 x 3 3x 2y 3xy 2 y 3 x y4 x 4 4x 3y 6x 2y 2 4xy3 y 4 x y4 x 4 4x 3y 6x 2y 2 4xy 3 y 4 nn 1 n2 2 . . . y nxy n1 y n x 2! nn 1 n2 2 . . . x yn x n nx n1y y ± nxy n1 y n x 2! x yn x n nx n1y Rational Zero Theorem If px an x n a n1x n1 . . . a1x a0 has integer coefficients, then every rational zero of p is of the form x rs, where r is a factor of a0 and s is a factor of an. Factoring by Grouping acx 3 adx 2 bcx bd ax 2cx d bcx d ax 2 bcx d Arithmetic Operations ab ac ab c ab a d ad c d b c bc b ab a c c a c ad bc b d bd a b a c bc ab a b c c c ab ba cd dc ab ac bc a a ac b b c Exponents and Radicals a0 1, a 0 ab x a xb x a xa y a xy n am amn ax a b x ax bx 1 ax a a12 ax a xy ay n a a1n n a n b n ab axy a xy Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. n n a a n b b Licensed to: iChapters User FORMULAS FROM GEOMETRY Triangle Sector of Circular Ring h a sin 1 Area bh 2 (Law of Cosines) c p average radius, w width of ring, in radians Area pw a θ h b c2 a 2 b2 2ab cos c (Pythagorean Theorem) a2 b2 Area ab a Circumference 2 b Equilateral Triangle h Area 3s2 s h A Right Circular Cone Trapezoid a h Area a b 2 h h r 2h 3 Lateral Surface Area rr2 h2 h Volume b r Frustum of Right Circular Cone r r 2 rR R 2h 3 Lateral Surface Area sR r s Volume b a h b h Right Circular Cylinder Circle Area r 2 Circumference 2 r Volume r 2h Lateral Surface Area 2 rh r Sector of Circle R r h Sphere 4 Volume r 3 3 Surface Area 4 r 2 s θ r Circular Ring p average radius, w width of ring Area R 2 r 2 2 pw a s Parallelogram in radians r2 Area 2 s r b a 2 b2 2 A area of base Ah Volume 3 s h 4 Area bh w Cone 3s 2 θ Ellipse Right Triangle c2 p r Wedge r p R w A area of upper face, B area of base A B sec A θ B Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. A108 Answers to Odd-Numbered Exercises This page contains answers for this chapter only. 19. (a) Order size, x Price Profit, P 90 20.15 10290 20.15 10260 3029.40 102 104 90 40.15 10490 40.15 10460 3057.60 106 90 60.15 10690 60.15 10660 3084.60 108 90 80.15 10890 80.15 10860 3110.40 110 90 100.15 11090 100.15 11060 3135.00 112 90 120.15 11290 120.15 11260 3158.40 (b) Order size, x Price Profit, P . . . . . . . . . 146 90 460.15 14690 460.15 14660 3372.60 148 90 480.15 14890 480.15 14860 3374.40 150 90 500.15 15090 500.15 15060 3375.00 152 90 520.15 15290 520.15 15260 3374.40 154 90 540.15 15490 540.15 15460 3372.60 . . . . . . . . . Maximum profit: $3375.00 (c) P x90 x 1000.15 x60 45x 0.15x2, x ≥ 100 (d) 150 units (e) 4000 (150, 3375) 100 300 0 21. The line should run from the power station to a point across the river 327 mile downstream. 23. x 40 units 25. $30,000 27. (a) 12 APPENDIX C (page A26) 1. (a) Fixed cost (b) 0 8 13 (b) July (c) The cosine factor; 9.90 (d) The term 0.02t would mean a steady growth of sales over time. In this case, the maximum sales in 2008 that is, on 49 ≤ t ≤ 60 would be about 11.6 thousand gallons. 29. (a) 10 (c) 10 (c) Yes; the extremum occurs when production costs are increasing at their slowest rate. 3. 4500 5. 300 7. 200 9. 200 11. $60 13. $35 15. x 3 17. Proof 0 0 (b) S 6.2 0.25t 1.5 sin 31. 17 3 ; elastic 0 9 2 t 0 (d) $12,000 33. 12; inelastic Copyright 2008 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. 9