Full derivations and solutions are obtained for the standard problems of quantum mechanics, mathematical physics, engineering math, and special relativity. Topics include the Del operator, gradient, curl, divergence, Fourier series and transforms, integration on the complex plane, matrices, Legendre polynomials, Bessel functions, Hermite polynomials, and other Special functions. Problems and solutions for self-study or for extra practice before tests. In numerical work, links to Wolfram alpha are included in the eBook. This is Volume III of the Tour of Undergraduate Physics series. Enjoy learning.