Characterization of best algebraic approximation by an algebraic modulus of smoothness

[摘要] The author introduced in an earlier paper a modulus of smoothness for non periodic functions based on an algebraic addition + defined on [-1, 1]. In this paper the Steklov Functions and an equivalent K-functional are given. Moreover, epsilon. characterization of best approximation by algebraic polynomials and the equivalence between the algebraic modulus and the Butter-Stens modulus, introduced by the Chebyshev translation method, are shown. (C) 1997 Academic Press.

[发布日期] 1997-04-01