A working knowledge of inequalities can be beneficial to the practicing engineer, and inequalities are central to the definitions of all limiting processes, including differentiation and integration. When exact solutions are unavailable, inconvenient, or unnecessary, inequalities can be used to obtain error bounds for numerical approximation. They can also lead to an understanding of the qualitative behavior of solutions. This guide to inequalities was written specifically with engineers and other applied scientists in mind, and helps fill the gap between college algebra-level treatments, and the formidable treatise on the subject that exist in the mathematics literature. To consolidate the learning process, every chapter ends with a rich collection of exercises.