Precalculus: Graphical, Numerical, Algebraic

1026 Pages·2010·19.17 MB·English

by  Franklin Demana

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Precalculus
G r a p h i c a l , N u m e r i c a l ,
EIGHTH EDITION
A l g e b r a i c
Franklin D. Demana
The Ohio State University
Bert K. Waits
The Ohio State University
Gregory D. Foley
Ohio University
Daniel Kennedy
Baylor School
6965_Demana_SE_FM_ppi-xxx.qxd 1/25/10 11:27 AM Page ii
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For permission to use copyrighted material, grateful acknowledgment is made to the copyright
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Many of the designations used by manufacturers and sellers to distinguish their products are
claimed as trademarks. Where those designations appear in this book, and Addison-Wesley was
aware of a trademark claim, the designations have been printed in initial caps or all caps.
*Advanced Placement Program and AP are registered trademarks of The College Board, which
was not involved in the production of, and does not endorse, this product.
Library of Congress Cataloging-in-Publication Data
Precalculus : graphical, numerical, algebraic / Franklin D. Demana . . . [et al.]. -- 8th ed.
p. cm.
Includes index.
ISBN 0-13-136906-7 (student edition) -- ISBN 0-13-136907-5 (annotated teacher’s edition)
1. Algebra--Textbooks. 2. Trigonometry--Textbooks. I. Demana, Franklin D., 1938-
QA154.3.P74 2010
512'.13--dc22
2009039915
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(high school binding)
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Foreword
Although much attention has been paid since 1990 to reforming calculus courses,
precalculus textbooks have remained surprisingly traditional. Now that The
College Board’s AP* Calculus curriculum is accepted as a model for a twenty-first
century calculus course, the path is cleared for a new precalculus course to match
the AP* goals and objectives. With this edition of Precalculus: Graphical,
Numerical, Algebraic, the authors of Calculus: Graphical, Numerical, Algebraic,
the best-selling textbook in the AP* Calculus market, have designed such a pre-
calculus course. For those students continuing to a calculus course, this precalcu-
lus textbook concludes with a chapter that prepares students for the two central
themes of calculus: instantaneous rate of change and continuous accumulation.
This intuitively appealing preview of calculus is both more useful and more rea-
sonable than the traditional, unmotivated foray into the computation of limits, and
it is more in keeping with the stated goals and objectives of the AP* courses and
their emphasis on depth of knowledge.
Recognizing that precalculus is a capstone course for many students, we include
quantitative literacy topics such as probability, statistics, and the mathematics of
finance and integrate the use of data and modeling throughout the text. Our goal
is to provide students with the critical-thinking skills and mathematical know-how
needed to succeed in college or any endeavor.
Continuing in the spirit of two earlier editions, we have integrated graphing tech-
nology throughout the course, not as an additional topic but as an essential tool for
both mathematical discovery and effective problem solving. Graphing technology
enables students to study a full catalog of basic functions at the beginning of the
course, thereby giving them insights into function properties that are not seen in
many books until later chapters. By connecting the algebra of functions to the
visualization of their graphs, we are even able to introduce students to parametric
equations, piecewise-defined functions, limit notation, and an intuitive under-
standing of continuity as early as Chapter 1. However, the advances in technology
and increased familiarity with calculators have blurred some of the distinctions
between solving problems and supporting solutions that we had once assumed to
be apparent. Therefore, we are asking that some exercises be solved without cal-
culators. (See the “Technology and Exercises” section.)
Once students are comfortable with the language of functions, the text guides them
through a more traditional exploration of twelve basic functions and their alge-
braic properties, always reinforcing the connections among their algebraic, graph-
ical, and numerical representations. This book uses a consistent approach to mod-
eling, emphasizing in every chapter the use of particular types of functions to
model behavior in the real world.
This textbook has faithfully incorporated not only the teaching strategies that have
made Calculus: Graphical, Numerical, Algebraicso popular, but also some of the
strategies from the popular Prentice Hall high school algebra series, and thus has
produced a seamless pedagogical transition from prealgebra through calculus for
*AP is a registered trademark of The College Board, which was not involved in the production of, and does
not endorse, this product.
Foreword iii
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students. Although this book can certainly be appreciated on its own merits, teach-
ers who seek continuity and vertical alignment in their mathematics sequence
might consider this pedagogical approach to be an additional asset of Precalculus:
Graphical, Numerical, Algebraic.
This textbook is written to address current and emerging state curriculum stan-
dards. In addition, we embrace NCTM’s Guiding Principles for Mathematics
Curriculum and Assessment and agree that a curriculum “must be coherent,
focused on important mathematics, and well articulated across the grades.” As sta-
tistics is increasingly used in college coursework, the workplace, and everyday
life, we have added a “Statistical Literacy” section in Chapter 9 to help students
see that statistical analysis is an investigative process that turns loosely formed
ideas into scientific studies. Our three sections on data analysis and statistics are
aligned with the GAISEReport published by the American Statistical Association;
however, they are not intended as a course in statistics but rather as an introduc-
tion to set the stage for possible further study in this area of growing importance.
References
Franklin, C., Kader, G., Mewborn, D., Moreno, J., Peck, R., Perry, M., and
Scheaffer, R. (2007). Guidelines for assessment and instruction in statistics edu-
cation (GAISE) report: A pre K-12 curriculum framework. Alexandria, VA:
American Statistical Association.
National Council of Teachers of Mathematics. (2009, June). Guiding principles
for mathematics curriculum and assessment. Reston, VA: Author. Retrieved
August 13, 2009, from http://www.nctm.org/standards/content.aspx?id=23273
iv Foreword
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Contents
CHAPTER P Prerequisites
P.1 Real Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Representing Real Numbers ~Order and Interval Notation ~Basic
Properties of Algebra ~Integer Exponents ~Scientific Notation
P.2 Cartesian Coordinate System . . . . . . . . . . . . . . . . . . . . . . . . 12
Cartesian Plane ~Absolute Value of a Real Number ~Distance
Formulas ~Midpoint Formulas ~Equations of Circles ~Applications
P.3 Linear Equations and Inequalities . . . . . . . . . . . . . . . . . . . 21
Equations ~Solving Equations ~Linear Equations in One Variable ~
Linear Inequalities in One Variable
P.4 Lines in the Plane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Slope of a Line ~Point-Slope Form Equation of a Line ~Slope-
Intercept Form Equation of a Line ~Graphing Linear Equations in
Two Variables ~Parallel and Perpendicular Lines ~Applying Linear
Equations in Two Variables
P.5 Solving Equations Graphically,
Numerically, and Algebraically . . . . . . . . . . . . . . . . . . . . . . 40
Solving Equations Graphically ~Solving Quadratic Equations ~
Approximating Solutions of Equations Graphically ~Approximating
Solutions of Equations Numerically with Tables ~Solving Equations
by Finding Intersections
P.6 Complex Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Complex Numbers ~Operations with Complex Numbers ~Complex
Conjugates and Division ~Complex Solutions of Quadratic Equations
P.7 Solving Inequalities Algebraically and Graphically . . . . . 54
Solving Absolute Value Inequalities ~Solving Quadratic Inequalities ~
Approximating Solutions to Inequalities ~Projectile Motion
Key Ideas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Review Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
CHAPTER 1 Functions and Graphs
1.1 Modeling and Equation Solving . . . . . . . . . . . . . . . . . . . . . . .64
Numerical Models ~Algebraic Models ~Graphical Models ~The Zero
Factor Property ~Problem Solving ~Grapher Failure and Hidden
Behavior ~A Word About Proof
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1.2 Functions and Their Properties . . . . . . . . . . . . . . . . . . . . . 80
Function Definition and Notation ~Domain and Range ~Continuity
~Increasing and Decreasing Functions ~ Boundedness ~Local and
Absolute Extrema ~Symmetry ~Asymptotes ~End Behavior
1.3 Twelve Basic Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
What Graphs Can Tell Us ~Twelve Basic Functions ~Analyzing
Functions Graphically
1.4 Building Functions from Functions . . . . . . . . . . . . . . . . . 110
Combining Functions Algebraically ~Composition of Functions ~
Relations and Implicitly Defined Functions
1.5 Parametric Relations and Inverses . . . . . . . . . . . . . . . . . . 119
Relations Defined Parametrically ~Inverse Relations and Inverse
Functions
1.6 Graphical Transformations . . . . . . . . . . . . . . . . . . . . . . . . . 129
Transformations ~Vertical and Horizontal Translations ~
Reflections Across Axes ~Vertical and Horizontal Stretches and
Shrinks ~Combining Transformations
1.7 Modeling with Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Functions from Formulas ~Functions from Graphs ~Functions
from Verbal Descriptions ~Functions from Data
Key Ideas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Review Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Chapter Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
CHAPTER 2 Polynomial, Power,
and Rational Functions
2.1 Linear and Quadratic Functions and Modeling . . . . . . . 158
Polynomial Functions ~Linear Functions and Their Graphs ~
Average Rate of Change ~Linear Correlation and Modeling ~
Quadratic Functions and Their Graphs ~Applications
of Quadratic Functions
2.2 Power Functions with Modeling . . . . . . . . . . . . . . . . . . . . 174
Power Functions and Variation ~Monomial Functions and
Their Graphs ~Graphs of Power Functions ~Modeling with
Power Functions
2.3 Polynomial Functions of
Higher Degree with Modeling . . . . . . . . . . . . . . . . . . . . . . 185
Graphs of Polynomial Functions ~End Behavior of Polynomial
Functions ~Zeros of Polynomial Functions ~Intermediate Value
Theorem ~Modeling
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2.4 Real Zeros of Polynomial Functions . . . . . . . . . . . . . . . . 197
Long Division and the Division Algorithm ~Remainder and Factor
Theorems ~Synthetic Division ~Rational Zeros Theorem ~Upper and
Lower Bounds
2.5 Complex Zeros and the
Fundamental Theorem of Algebra . . . . . . . . . . . . . . . . . . 210
Two Major Theorems ~Complex Conjugate Zeros ~Factoring with
Real Number Coefficients
2.6 Graphs of Rational Functions . . . . . . . . . . . . . . . . . . . . . . 218
Rational Functions ~Transformations of the Reciprocal Function ~
Limits and Asymptotes ~Analyzing Graphs of Rational Functions ~
Exploring Relative Humidity
2.7 Solving Equations in One Variable . . . . . . . . . . . . . . . . . . 228
Solving Rational Equations ~Extraneous Solutions ~Applications
2.8 Solving Inequalities in One Variable . . . . . . . . . . . . . . . . . 236
Polynomial Inequalities ~Rational Inequalities ~Other Inequalities
~Applications
Key Ideas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
Review Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
Chapter Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
CHAPTER 3 Exponential, Logistic,
and Logarithmic Functions
3.1 Exponential and Logistic Functions . . . . . . . . . . . . . . . . . 252
Exponential Functions and Their Graphs ~The Natural Base e~
Logistic Functions and Their Graphs ~Population Models
3.2 Exponential and Logistic Modeling . . . . . . . . . . . . . . . . . . 265
Constant Percentage Rate and Exponential Functions ~Exponential
Growth and Decay Models ~Using Regression to Model Population
~Other Logistic Models
3.3 Logarithmic Functions and Their Graphs . . . . . . . . . . . . 274
Inverses of Exponential Functions ~Common Logarithms—Base 10
~Natural Logarithms—Base e~Graphs of Logarithmic Functions ~
Measuring Sound Using Decibels
3.4 Properties of Logarithmic Functions . . . . . . . . . . . . . . . . 283
Properties of Logarithms ~Change of Base ~Graphs of Logarithmic
Functions with Base b~Re-expressing Data
3.5 Equation Solving and Modeling . . . . . . . . . . . . . . . . . . . . . 292
Solving Exponential Equations ~Solving Logarithmic Equations ~
Orders of Magnitude and Logarithmic Models ~Newton’s Law of
Cooling ~Logarithmic Re-expression
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3.6 Mathematics of Finance . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
Interest Compounded Annually ~Interest Compounded kTimes per
Year ~Interest Compounded Continuously ~Annual Percentage
Yield ~Annuities—Future Value ~Loans and Mortgages—Present Value
Key Ideas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
Review Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
Chapter Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
CHAPTER 4 Trigonometric Functions
4.1 Angles and Their Measures . . . . . . . . . . . . . . . . . . . . . . . . 320
The Problem of Angular Measure ~Degrees and Radians ~Circular
Arc Length ~Angular and Linear Motion
4.2 Trigonometric Functions of Acute Angles . . . . . . . . . . . . 329
Right Triangle Trigonometry ~Two Famous Triangles ~Evaluating
Trigonometric Functions with a Calculator ~Common Calculator Errors When
Evaluating Trig Functions ~Applications of Right Triangle Trigonometry
4.3 Trigonometry Extended: The Circular Functions . . . . . 338
Trigonometric Functions of Any Angle ~Trigonometric
Functions of Real Numbers ~Periodic Functions ~The 16-Point
Unit Circle
4.4 Graphs of Sine and Cosine: Sinusoids . . . . . . . . . . . . . . . 350
The Basic Waves Revisited ~Sinusoids and Transformations ~
Modeling Periodic Behavior with Sinusoids
4.5 Graphs of Tangent, Cotangent, Secant,
and Cosecant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361
The Tangent Function ~The Cotangent Function ~The Secant
Function ~The Cosecant Function
4.6 Graphs of Composite Trigonometric Functions . . . . . . . 369
Combining Trigonometric and Algebraic Functions ~Sums and
Differences of Sinusoids ~Damped Oscillation
4.7 Inverse Trigonometric Functions . . . . . . . . . . . . . . . . . . . 378
Inverse Sine Function ~Inverse Cosine and Tangent Functions ~
Composing Trigonometric and Inverse Trigonometric Functions ~
Applications of Inverse Trigonometric Functions
4.8 Solving Problems with Trigonometry . . . . . . . . . . . . . . . . 388
More Right Triangle Problems ~Simple Harmonic Motion
Key Ideas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399
Review Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399
Chapter Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402
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CHAPTER 5 Analytic Trigonometry
5.1 Fundamental Identities . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404
Identities ~Basic Trigonometric Identities ~Pythagorean Identities
~Cofunction Identities ~Odd-Even Identities ~Simplifying
Trigonometric Expressions ~Solving Trigonometric Equations
5.2 Proving Trigonometric Identities . . . . . . . . . . . . . . . . . . . 413
A Proof Strategy ~Proving Identities ~Disproving Non-Identities ~
Identities in Calculus
5.3 Sum and Difference Identities . . . . . . . . . . . . . . . . . . . . . . 421
Cosine of a Difference ~Cosine of a Sum ~Sine of a Difference or
Sum ~Tangent of a Difference or Sum ~Verifying a Sinusoid
Algebraically
5.4 Multiple-Angle Identities . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
Double-Angle Identities ~Power-Reducing Identities ~Half-Angle
Identities ~Solving Trigonometric Equations
5.5 The Law of Sines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434
Deriving the Law of Sines ~Solving Triangles (AAS, ASA) ~The
Ambiguous Case (SSA) ~Applications
5.6 The Law of Cosines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 442
Deriving the Law of Cosines ~Solving Triangles (SAS, SSS) ~
Triangle Area and Heron’s Formula ~Applications
Key Ideas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450
Review Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450
Chapter Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 454
CHAPTER 6 Applications of Trigonometry
6.1 Vectors in the Plane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456
Two-Dimensional Vectors ~Vector Operations ~Unit Vectors ~
Direction Angles ~Applications of Vectors
6.2 Dot Product of Vectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467
The Dot Product ~Angle Between Vectors ~Projecting One Vector
onto Another ~Work
6.3 Parametric Equations and Motion . . . . . . . . . . . . . . . . . . 475
Parametric Equations ~Parametric Curves ~Eliminating the
Parameter ~Lines and Line Segments ~Simulating Motion with a
Grapher
6.4 Polar Coordinates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 487
Polar Coordinate System ~Coordinate Conversion ~Equation
Conversion ~Finding Distance Using Polar Coordinates
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6.5 Graphs of Polar Equations . . . . . . . . . . . . . . . . . . . . . . . . . 494
Polar Curves and Parametric Curves ~Symmetry ~Analyzing Polar
Graphs ~Rose Curves ~Limaçon Curves ~Other Polar Curves
6.6 De Moivre’s Theorem and nth Roots . . . . . . . . . . . . . . . . 503
The Complex Plane ~Trigonometric Form of Complex Numbers ~
Multiplication and Division of Complex Numbers ~Powers of
Complex Numbers ~Roots of Complex Numbers
Key Ideas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513
Review Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 514
Chapter Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 517
CHAPTER 7 Systems and Matrices
7.1 Solving Systems of Two Equations . . . . . . . . . . . . . . . . . . 520
The Method of Substitution ~Solving Systems Graphically ~
The Method of Elimination ~Applications
7.2 Matrix Algebra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 530
Matrices ~Matrix Addition and Subtraction ~Matrix Multiplication
~Identity and Inverse Matrices ~Determinant of a Square Matrix ~
Applications
7.3 Multivariate Linear Systems and Row Operations . . . . . 544
Triangular Form for Linear Systems ~Gaussian Elimination ~
Elementary Row Operations and Row Echelon Form ~Reduced
Row Echelon Form ~Solving Systems with Inverse Matrices ~
Applications
7.4 Partial Fractions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 557
Partial Fraction Decomposition ~Denominators with Linear
Factors ~Denominators with Irreducible Quadratic Factors ~
Applications
7.5 Systems of Inequalities in Two Variables . . . . . . . . . . . . . 565
Graph of an Inequality ~Systems of Inequalities ~Linear Programming
Key Ideas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573
Review Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573
Chapter Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 577
CHAPTER 8 Analytic Geometry in
Two and Three Dimensions
8.1 Conic Sections and Parabolas . . . . . . . . . . . . . . . . . . . . . . 580
Conic Sections ~Geometry of a Parabola ~Translations of
Parabolas ~Reflective Property of a Parabola
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