Posts

Showing posts from May 13, 2019

Weiertrass Approximation Theorem

Image
Weiertrass Approximation Theorem :   Statement :                If f is a real continuous function defined on a closed interval [a,b] then there exists a sequence of real polynomials {Pₙ} which converges uniformly to f(x) on [a,b] i.e lim Pₙ(x)=f(x)                                                    n-->∞ converges uniformly on [a,b] . Proof :        If a=b , the conclusion follows by taking  Pₙ(x) to be a constant polynomial , defined by   Pₙ(x) = f(a) for all n . We may thus assume that a<b . We next observe that a linear transformation                          x' = (x-a) / (b-a) is a continuous mapping of  [a,b] onto [1,0] . Accordingly , we assume without ...