Trigonometry, 12th Edition © 2021

Trigonometry, published by Pearson, balances the conceptual understanding and analytical skills needed to succeed in mathematics. With the integrated review now available digitally, teachers can easily accommodate varying levels of student preparation.

  • Curricular adaptability and flexibility
  • Personalized learning to support each student
  • New Personal Inventory Assessments
  • Robust content on MyMathLab® platform from Pearson

Trigonometry Program with Digital Resources

Guide students through the concepts of trigonometry with a systematic approach that engages students in the learning process.

Improved Student Results

Integrated Review provides supporting resources for the main course content plus additional assignments and study aids for students who will benefit from remediation.

Trusted Content

Relating Concepts exercises help students connect topics and develop problem-solving skills as they compare and contrast ideas, identify and describe patterns, and extend concepts to new situations.

Curricular Flexibility

MyMathLab® for School allows teachers to build their own assignments, teach multiple sections, and set prerequisites so the course best fits everyone’s needs.


Self-Reflection and Engagement

MyMathLab® for School from Pearson combines trusted content and a flexible platform to personalize the learning experience and improve results for each student.

Trigonometry Teaching Solutions

  • Learner Support
  • Updated Video Program
  • Conceptual Reinforcement
  • Review and Test Preparation
  • Personal Inventory Assessments
    33 Personal Inventory Assessments promote self-reflection and engagement in students on topics such as Stress Management, Diagnosing Poor Performance, Enhancing Motivation, and Time Management.
  • MyNotes
    MyNotes offer structure for students as they watch videos or read text with ample space for note-taking and prompts to reflect on what they have learned.
  • Integrated Review Worksheets
    Integrated Review Worksheets prepare students for College Algebra material. They include key terms and guided examples with ample space for students to work and reference where in MyMathLab for School to look for help.
  • Quick Reviews
    Quick Reviews cover Key Definitions through the detailed solution process for every example in the textbook.
  • Example Solutions
    Example Solutions walk students through the detailed solution process for every example in the textbook.
  • Essential College Algebra Series
    The new Essential College Algebra Series covers the foundational topics your students need to master to be successful in the course. Interactive questions are embedded throughout to allow students to stop and think about the next step. Online worksheets are available to guide students through the material.
  • Concept Preview Exercises
    Concept Preview Exercises begin each homework section to ensure students’ understanding of vocabulary and basic concepts. Concept Check Exercises focus on mathematical thinking and conceptual understanding.
  • Example Pointers
    Pointers in the examples provide on-the-spot reminders and warnings about common pitfalls. Examples offer additional side comments where appropriate in the step-by-step solutions. More section references to previously covered materials have been added.
  • Now Try Exercises
    Now Try exercises conclude every example with a reference to one or more parallel, odd-numbered exercises from the corresponding exercise set. Students are able to immediately apply and reinforce the concepts and skills presented in the examples.
  • Quizzes
    Quizzes appear periodically throughout the chapter for students to check their progress. Answers are located at the back of the text.
  • Summary Exercises
    Summary Exercises offer mixed review, requiring students to decide which methods covered in the chapter should apply to a particular problem.
  • Cumulative Review Assignments
    Cumulative Review assignments, drawn from best practices developed by author Callie Daniels, can be assigned for each chapter in MyMathLab for School.
  • Chapter Reviews and Test Prep
    Chapter Reviews and Test Prep conclude every chapter with a Summary, featuring a section-by-section list of Key Terms and New Symbols. A Quick Review of important concepts is presented alongside corresponding examples. Review Exercises and a Chapter Test cover all the skills learned

Empower Your Math Students with the MyMathLab® Platform from Pearson


MyMathLab® for School from Pearson provides personalized and adaptable teaching and learning resources for blended or digital mathematics classes.

More About Trigonometry

  • Marge Lial Author Bio
    Marge Lial (late) was always interested in math; it was her favorite subject in the first grade! Marge's intense desire to educate both her students and herself has inspired the writing of numerous best-selling textbooks. Marge, who received Bachelor's and Master's degrees from California State University at Sacramento, was affiliated with American River College. An avid reader and traveler, her travel experiences often found their way into her books as applications, exercise sets, and feature sets. Her interest in archeology led to trips to various digs and ruin sites, producing some fascinating problems for her textbooks involving such topics as the building of Mayan pyramids and the acoustics of ancient ball courts in the Yucatan.
  • John Hornsby Author Bio
    When John Hornsby enrolled as an undergraduate at Louisiana State University, he was uncertain whether he wanted to study mathematics education or journalism. His ultimate decision was to become a teacher, but after twenty-five years of teaching at the high school and university levels and fifteen years of writing mathematics textbooks, both of his goals have been realized. His love for both teaching and for mathematics is evident in his passion for working with students and fellow teachers as well. His specific professional interests are recreational mathematics, mathematics history, and incorporating graphing calculators into the curriculum. John's personal life is busy as he devotes time to his family (wife Gwen, and sons Chris, Jack, and Josh), and has been an avid baseball fan all of his life. John's other hobbies include numismatics (the study of coins) and record collecting. He loves the music of the 1960s and has an extensive collection of the recorded works of Frankie Valli and the Four Seasons.
  • Terry McGinnis Author Bio
    A native Midwesterner, Terry McGinnis received her Bachelor’s of Science in Elementary Education with a concentration in Mathematics from Iowa State University. She has taught elementary and middle school mathematics, and developed and implemented the curriculum used with her students. Terry has been involved in college mathematics publishing for over 20 years, working with a variety of authors on textbooks in both developmental mathematics and precalculus. After working behind the scenes on many of the Lial/Hornsby textbooks and supplements for over 10 years, Terry joined Margaret Lial and John Hornsby in 2002 as coauthor of their developmental mathematics series. When not working, Terry enjoys spinning at a local health club, walking, and reading fiction. She is the devoted mother of two sons, Andrew and Tyler.
  • Callie Daniels Author Bio
    Callie Daniels has always had a passion for learning mathematics and brings that passion into the classroom with her students. She attended the University of the Ozarks where she earned a bachelor’s degree in Secondary Mathematics Education. She has two master’s degrees: one in Applied Mathematics and Statistics from the University of Missouri–Rolla, the second in Adult Education from the University of Missouri–St. Louis. Her professional interests include improving success in the community college mathematics sequence, using technology to enhance students’ understanding of mathematics, and creating materials that support classroom teaching and student understanding. She is able to pursue these interests as a contributor on the Lial Developmental Math series, and a co-author on the Precalculus series.
  • Table of Contents

    Resources for Success

    R. Algebra Review
    R.1 Basic Concepts from Algebra
    R.2 Real Number Operations and Properties
    R.3 Exponents, Polynomials, and Factoring
    R.4 Rational Expressions
    R.5 Radical Expressions
    R.6 Equations and Inequalities
    R. 7 Rectangular Coordinates and Graphs
    R.8 Functions
    R.9 Graphing Techniques

    1. Trigonometric Functions
    1-1 Angles
    1-2 Angle Relationships and Similar Triangles
    1-3 Trigonometric Functions
    1-4 Using the Definitions of the Trigonometric Functions
    Test Prep
    Review Exercises

    2. Acute Angles and Right Triangles
    2-1 Trigonometric Functions of Acute Angles
    2-2 Trigonometric Functions of Non-Acute Angles
    2-3 Approximations of Trigonometric Function Values
    2-4 Solutions and Applications of Right Triangles
    2-5 Further Applications of Right Triangles
    Test Prep
    Review Exercises

    3. Radian Measure and the Unit Circle
    3-1 Radian Measure
    3-2 Applications of Radian Measure
    3-3 The Unit Circle and Circular Functions
    3-4 Linear and Angular Speed
    Test Prep
    Review Exercises

    4. Graphs of the Circular Functions
    4-1 Graphs of the Sine and Cosine Functions
    4-2 Translations of the Graphs of Sine and Cosine Functions
    4-3 Graphs of the Tangent and Cotangent Functions
    4-4 Graphs of the Secant and Cosecant Functions
    4-5 Harmonic Motion
    Test Prep
    Review Exercises

    5. Trigonometric Identities
    5-1 Fundamental Identities
    5-2 Verifying Trigonometric Identities
    5-3 Sum and Difference Identities for Cosine
    5-4 Sum and Difference Identities for Sine and Tangent
    5-5 Double-Angle Identities
    5-6 Half-Angle Identities
    Test Prep
    Review Exercises

    6. Inverse Circular Functions and Trigonometric Equations
    6-1 Inverse Circular Functions
    6-2 Trigonometric Equations I
    6-3 Trigonometric Equations II
    6-4 Equations Involving Inverse Trigonometric Functions
    Test Prep
    Review Exercises

    7. Applications of Trigonometry and Vectors
    7-1 Oblique Triangles and the Law of Sines
    7-2 The Ambiguous Case of the Law of Sines
    7-3 The Law of Cosines
    7-4 Geometrically Defined Vectors and Applications
    7-5 Algebraically Defined Vectors and the Dot Product
    Test Prep
    Review Exercises

    8. Complex Numbers, Polar Equations, and Parametric Equations
    8-1 Complex Numbers
    8-2 Trigonometric (Polar) Form of Complex Numbers
    8-3 The Product and Quotient Theorems
    8-4 De Moivre’s Theorem
    8-5 Polar Equations and Graphs
    8-6 Parametric Equations, Graphs, and Applications
    Test Prep
    Review Exercises

    Answers to Selected Exercises
    Photo Credits

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