This text is designed for an in-depth course in trigonometry. Although the development of trigonometry begins on page one, the authors realize that many students may have completed algebra and geometry courses some time ago. Therefore, they have included algebra and geometry reminders throughout the text where they know from their teaching experience that many students need help in recalling ideas that are necessary to develop trigonometry. While it assumes no previous knowledge of trigonometry, this book shows how trigonometry can be used in many fields. It also develops algebra skills so that students will be thoroughly prepared to continue their study of mathematics and science. The use of graphing calculators has been incorporated throughout the text to reduce the labor of calculations and to expand the students' understanding of concepts and give students the opportunity to explore relationships.