It is with great pleasure that we offer the ninth edition of Trigonometry. Over the years, the text has been shaped and adapted to meet the changing needs of both students and educators, and this edition faithfully continues that process. As always, we have taken special care to respond to the specific suggestions of users and reviewers through enhanced discussions, new and updated examples and exercises, helpful features, and an extensive package of supplements and study aids. We believe the result is an easy-to-use, comprehensive text that is the best edition yet. Students planning to continue their study of mathematics in calculus, statistics, or other disciplines, as well as those taking trigonometry as their final mathematics course, will benefit from the text´s student-oriented approach. In particular, we have added NEW! pointers to examples, included NEW! Quizzes in each chapter, revised 25% of the exercises, and added NEW! Connecting Graphs with Equations problems to make the book even more accessible for students. Additionally, we believe instructors will welcome the expanded Annotated Instructor´s Edition that now includes an extensive set of NEW! Classroom Examples, in addition to helpful Teaching Tips and on-page answers for almost all text exercises.