In Chap. 3 , vector fields are introduced, and the calculus of vectors is developed. This includes both differential vector calculus (gradient, divergence, curl, and Laplacian operations) and integral vector calculus (line, surface, and volume integrals). The Einstein summation convention and index notation are again used to develop numerous identities. Prominent theorems are proved to include the divergence theorem, Stokes’ theorem, and Green’s theorem. In-chapter examples and end-of-chapter problems are included to reinforce introduced concepts and to give readers a chance to practice the relevant mathematics.