In this new edition of Precalculus, Seventh Edition, the authors encourage graphical, numerical, and algebraic modeling of functions as well as a focus on problem solving, conceptual understanding, and facility with technology.  They responded to many helpful suggestions provided by students and teachers in order to create a book that is designed for instructors and written for students.   As a result, we believe that the changes made in this edition make this the most effective precalculus text available today.