This book is an introduction to calculus and its applications to the management, social, behavioral, and biomedical sciences, and other fields. The only prerequisites are some knowledge of algebra, functions, and graphing, which are reviewed in Chapter 1 and in greater detail in the Algebra Review appendix. 　　Our foremost goal in writing these books has been to make the content as accessible to as many students as possible. Over time, we have introduced various features to address the changing needs of students as they learn the essential techniques and fundamental concepts of calculus. In order maintain students’ interest and provide them with the most accurate and engaging textbook, we have been guided by the following principles. 　　1. Informal proofs 　　2. Integration of mathematics and applications 　　3. Rapid start 　　4. Just-in-time review 　　5. Continual algebra reinforcement