The first of a two-volume set, Mathematical The Basics provides a masterful introduction to the mathematical methods encountered by undergraduate students in physics, chemistry, and engineering. Topics include vectors and Cartesian tensors, vector calculus, Lorentz tensors, curvilinear coordinates, linear vector spaces and linear operators, eigenvalues and eigenvectors, matrix representations and diagonalization of matrices, complex variables, analytic functions, Taylor and Laurent series, contour integrals, residue theorem and applications, and method of steepest descent. Numerous worked examples and problems are featured to demonstrate principles and facilitate learning.