Presents a down-to-earth approach to using differential and integral equations when tackling significant problems in the physical sciences, engineering, and applied mathematics. The author incorporates developments that have altered the field of applied mathematics in recent decades< — >particularly in areas of modeling, Fourier analysis, fixed-point theorems, inverse problems, asymptotics, and nonlinear methods. The second edition retains popular features such as chapter introductions, clear explanations of basic concepts, and plentiful exercises