2019
Том 71
№ 6

# Fedorenko A. S.

Articles: 3
Brief Communications (Ukrainian)

### The Best $m$-Term Trigonometric Approximations of the Classes $L_{\beta ,p}^\Psi$ in Uniform Metric

Ukr. Mat. Zh. - 2004. - 56, № 1. - pp. 129-132

We obtain an exact order estimate for the best approximation of the classes $L_{\beta ,p}^\Psi$ of functions of one variable in the space $L_{∞}$.

Brief Communications (Russian)

### Bestm-term trigonometric approximations of classes of (Ψ, β)-differentiable functions of one variable

Ukr. Mat. Zh. - 2000. - 52, № 6. - pp. 850–855

We obtain an estimate exact in order for the best trigonometric approximation of classes $L_{\beta ,p}^\psi$ of functions of one variable in the spaceL q in the case where 1<p≤2≤q<∞.

Brief Communications (Ukrainian)

### On the best $m$-term trigonometric and orthogonal trigonometric approximations of functions from the classes $L^{Ψ}_{β,ρ}$

Ukr. Mat. Zh. - 1999. - 51, № 12. - pp. 1719-1721

We obtain estimates exact in order for the best trigonometric and orthogonal trigonometric approximations of the classes $L^{Ψ}_{β,ρ}$ of functions of one variable in the space $L_q$ in the case $2 < p < q < ∞$.