O Teorema de Stone-Weierstrass e aplicações

Abstract

The aim of this dissertation is to prove and apply the Weierstrass Approximation Theo- rem, on the approximation of continuous functions on bounded closed intervals by polyno- mials, and the Stone-Weierstrass Theorem, on the approximation of continuous functions on compact topological spaces. As applications of the Weierstrass Approximation Theo- rem we deal with the momentum problem for continuous functions and the approximation of continuous functions on the line by in¯nitely di®erentiable functions. As applications of the Stone-Weierstrass Theorem we prove that the space C(K) of continuous functions on the compact K is separable if and only if K is metrizable and the existence of a com- pact space K such that C(K) is isometrically isomorphic to the space `1 of bounded sequences.