Interpolation and Approximation (Dover Books on Mathematics);

Interpolation and approximation offer important applications in computer science and elsewhere. This intermediate-level survey by a noted authority abounds in useful examples of related subjects and has been praised for its level of clarity and reliance on well-presented and useful examples.
A brief introductory chapter presents helpful definitions and theorems. Subsequent chapters explore interpolation, remainder theory, convergence theorems for interpolatory processes, and some problems of infinite interpolation. Additional topics include uniform and best approximation, least square approximation, Hilbert space, orthogonal polynomials, the theory of closure and completeness, expansion theorems for orthogonal functions, degree of approximation, and approximation of linear functionals. A familiarity with real and complex variable theory and linear algebra is assumed. 1963 edition.