This text introduces trigonometry first with a unit circle approach and then with the right triangle. As the best-selling text in the field, Trigonometry provides unparalleled exercises, motivating real-life applications, a supportive pedagogical design, and innovative ancillaries and resources, making it a complete solution for both students and instructors. New! Model It real-life applications in nearly every text section are multi-part exercises that require students to generate and analyze mathematical models. First referenced in the Why You Should Learn It at the beginning of each section, these interesting applications illustrate why it is important to learn the concepts in each section. New! Enlarged printable graphs in many exercise sets contain problems asking students to draw on the graph provided. Because this is not feasible in the actual text, printable enlargements of these graphs are available on the web site www.mathgraphs.com. New! Proofs in Mathematics shows the proofs of selected theorems and demonstrates different proof techniques. For added convenience, in the Sixth Edition these proofs have been moved from an appendix to the end of relevant chapters. New! P.S. Problem Solving, at the conclusion of each chapter, features a collection of thought-provoking and challenging exercises that further explore and expand upon the concepts of the chapter. These exercises have unique characteristics that set them apart from traditional algebra and trigonometry exercises. New! A wealth of student success tools includes: How to Study This Chapter, a chapter-opening study guide that includes What you should learn (section-opening objectives), Important Vocabulary, a list of Study Tools, and a list of Additional Resources to help the student prepare for the chapter; Why you should learn it, a section-opening, real-life application or a reference to other branches of mathematics, illustrating the relevance of the section's content; and What did you learn?, a concise chapter summary organized by section. These objectives are correlated to the chapter Review Exercises to help students prepare for exams. Abundant, up-to-date Real-Life Applications are integrated throughout the examples and exercises and identified by a globe icon to reinforce the relevance of the concepts being learned. A wide variety of Exercises, including computational, conceptual, and applied problems are carefully graded in difficulty to allow students to gain confidence as they progress. Each exercise set includes Synthesis Exercises that promote further exploration of mathematical concepts, critical-thinking skills, and writing about mathematics, and Review Exercises that reinforce previously learned skills and concepts. Special Algebra of Calculus examples and exercises highlight the algebraic techniques used in calculus to show students how the mathematics they are learning now will be used in future courses. Optional graphing technology support is provided in marginal point-of-use instructions that encourage the use of graphing technology as a tool to visualize mathematical concepts, to verify other solution methods, and to facilitate computation. In addition, the section An Introduction to Graphing Utilities helps the student become familiar with the basic functionality of a graphing utility. The use of technology is optional in this text; all exercises that require the use of a graphing utility are clearly identified by an icon. Explorations preceding the introduction of selected topics provide the opportunity to engage students in active discovery of mathematical concepts and relationships, often through the power of technology. Explorations strengthen students' critical- thinking skills and help develop an intuitive understanding of theoretical concepts. All Examples have been carefully chosen to illustrate a particular mathematical concept or problem-solving skill. Every example contains step-by-step solutions, most with line-by-line explanations that lead students through the solution process, making it easy for students to understand the concepts being explained. Additional carefully crafted learning tools designed to create a rich learning environment include Study Tips, Historical Notes, Writing about Mathematics, Chapter Review Exercises, Chapter Tests, and Cumulative Tests. A clear, predictable layout, in which solutions and explanations begin and end on the same page, allows students to see concepts and solutions as a whole, without page-turning distractions.