We obtain an estimate of the deviation of de la Vallee Poussin sums V_{n,n/2}(f;x) from continuous functions f, expressed in terms of values of theirs modulus of continuity. It is established that… Expand

We obtain asymptotic equalities for least upper bounds of deviations in the uniform metric of de la Vallée Poussin sums on the sets CβqHω of Poisson integrals of functions from the class Hω generated… Expand

The approximation characteristics of trigonometric sums of special type on the class of ()-differentiable (in the sense of A. I. Stepanets) periodical functions are studied. Because of agreement… Expand

We obtain the estimates for the best approximation in the uniform metric of the classes of 2π-periodic functions whose (Ψ,β)-derivatives have a given majorant ω of the modulus of continuity. It is… Expand