The present book emphasizes basic results in functional and classical analysis, published in the last two decades. Markov moment problem, polynomial approximation on unbounded subsets, invariant subspaces and balls for bounded linear operators, convexity and convex optimization, a global variant of Newton's method for convex functions and operators and its connection to contraction principle, special functional equations (including the case of complex analytic functions and operatorial equations), approximating the perimeter of theellipse by means of a Leibniz series are discussed.