Trigonometric Approximation by Modulus of Smoothness in Lp,α (X)

Abstract

In this paper, we study the approximate properties of functions by means of trigonometric polynomials in weighted spaces. Relationships between modulus of smoothness of function derivatives and those of the jobs themselves are introduced. In the weighted spaces we also proved of theorems about the relationship between the derivatives of the polynomials for the best approximation and the best approximation of the functions

Keywords

• keywords: best approximation , weighted space , trigonometric polynomials, modulus of smoothness