This thesis takes a closer look at three fundamental Classical Theorems in Real Analysis. First, for the Bolzano Weierstrass Theorem, we will be interested in constructing a convergent subsequence from a non-convergent bounded sequence. Such a subsequence is guaranteed to exist, but it is often not obvious what it is, e.g., if an = sin n. Next, the H¨older Inequality gives an upper bound, in terms of p ∈ [1,∞], for the the integral of the product of two functions. We will find the value of p that gives the best (smallest) upper-bound, focusing on the Beta and Gamma integrals. Finally, for the Weierstrass Polynomial Approximation, we will find the degree of the approximating polynomial for a variety of functions. We choose examples in which the approximating polynomial does far worse than the Taylor polynomial, but also work with continuous non-differentiable functions for which a Taylor expansion is impossible.

Submitted by ANA KARLA PEREIRA RODRIGUES (anakarla_@hotmail.com) on 2017-08-10T12:12:27Z No. of bitstreams: 1 arquivototal.pdf: 955147 bytes, checksum: f6b8d3b1e6ba8fba22d9e0a28e6685fc (MD5) / Made available in DSpace on 2017-08-10T12:12:27Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 955147 bytes, checksum: f6b8d3b1e6ba8fba22d9e0a28e6685fc (MD5) Previous issue date: 2016-08-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work, we present a version little know of the famous Hölder's Inequality, considering the context of Lp and lp spaces for mixed norms. We show how a suitable use this inequality has influencied positively others classical inequalities, to highlight, the multilinear inequalities of Bohnenblust-Hille and Hardy-Littlewood. / No presente trabalho, apresentamos uma versão pouco conhecida da famosa Desigualdade de Hölder, considerando o contexto dos espaços Lp e lp com normas mistas. Mostramos como o uso adequado desta desigualdade vem influenciando positivamente outras desigualdades clássicas, a destacar, as desigualdades multilineares de Bohnenblust-Hille e Hardy-Littlewood.