This book emphasizes some basic results in functional and classical analysis, including Hahn-Banach-type theorems, the Markov moment problem, polynomial approximation on unbounded subsets, convexity and convex optimization, elements of operator theory, a global method for convex monotone operators and a connection with the contraction principle. It points out the connection between linear continuous operators and convex continuous operators, and establishes their relationships with other fields of mathematics and physics. The book will appeal to students, PhD aspirants, researchers, professors, engineers, and any reader interested in mathematical analysis or its applications.