The Fourth Edition of College Algebra helps students see the dynamic link between concepts and applications. The authors' hallmark approach, the Aufmann Interactive Method, encourages students to interact with math by presenting an annotated example, then guiding students with a Try Exercise, and finally presenting a worked-out solution for immediate reinforcement of the concept. An Instructor's Annotated Edition, unlike any other offered for this course, features reduced student text pages with special instructor resources in the margins: teaching tips, extra examples, ideas for reinforcing concepts, discussion suggestions, highlighted vocabulary and symbols, challenge problems, quizzes, suggested assignments, and references to transparencies that may be found both in the Instructor's Resource Manual and on the web site. Side-by-Side Solutions to examples pair an algebraic solution and a graphical representation to accommodate different learning styles. Integrated web resources include selected Take Note boxes (identified by a special web icon) which direct students to an interactive example or a downloadable file on the web site. Exploring Concepts with Technology, a special end-of-chapter feature, expands on ideas introduced in the text by using technology to investigate extended mathematical applications or topics. Projects at the end of each exercise set are designed to encourage students (or groups of students) to research and write about mathematics and its applications. Additional Projects are included in the Instructor's Resource Manual and on the book's web site. Take Note and Math Matters (formerly called Point of Interest) margin notes alert students about interesting aspects of math history, applications, and points that require special attention.