Let WrH
w
be the subclass of those functions of Cr[a, b], for which ω(f
(r),δ)⩽ω(δ), where ω(δ) is a given modulus of continuity, and Pn be the space of algebraic polynomials of degree at most n and πn(f) be the polynomial of best approximation for f(x) on [a, b]. Estimates for
and moduli...... hiện toàn bộ