Warren Esty's Precalclus is intended as a bridge from high school Algebra II and trigonometry to college calculus. It fills the need for a text that delves deeper into the power of algebra and algebraic notation than other texts which merely emphasize calculation skills. The text includes the usual precalculus material, including functions, powers, polynomials, logarithms, exponentials, and trigonometry, while placing special emphasis on learning how to read and use mathematical symbolism. Precalculusis not designed as a terminal course. On the contrary, it is designed to help students retain what they learn. It emphasizes tools for retention that other texts omit. For example, in addition to the usual calculation problems for practice, the text has problems that ask for an illustration, explanation, or a statement in mathematical notation, rather than just a computation. Some problems ask for the plan and not the answer, which helps students focus on what they are doing and why, rather than just focusing on getting a numerical answer. Typically, students do well with algebra if the context is simple and the computation is with numbers. However, they have a harder time at the deeper level required to do word problems and calculus, which ask students to write about operations applied to letters (variables). Thus, texts that duplicate the calculation-oriented algebra of high school without stressing algebraic symbolism¿with letters as they appear every day in calculus¿fall short in preparing students for higher math. Precalculus makes sure students become used to working with letters, not just numbers. The text helps students: learn the facts and methods of algebra and trigonometry so well that they have them at their command (even without recent review) learn how and when to use calculators and graphing technology become good at word problems learn to read symbolic mathematics fluently learn to work abstractly with symbols and functions as comfortably as with numbers learn to explain key general results symbolically and in English, and illustrate them with pictures, as an aid to retention