The Voronovskaya theorem for some linear positive operators in exponential weight spaces

In this note we give the Voronovskaya theorem for some linear positive operators of the Szasz-Mirakjan type defined in the space of functions continuous on [0, +∞) and having the exponential growth at infinity. Some approximation properties of these operators are given in [3], [4]

Approximation properties of the picard singular integral in exponential weighted spaces

In this note we give some direct and inverse approximation theorems for the Picard singular integral in the exponential weighted spaces and some generalized Hölder spaces

Approximation properties of modified Stancu beta operators

In this paper we give approximation theorems for modified Stancu beta operators of differentiable functions. The Stancu beta operators were examined in [8, 1, 2, 5] and other papers

The Picard and the Gauss-Weierstrass singular integrals of functions in two variables

We study some approximation properties of the Picard and the Gauss-Weierstrass singular integrals of functions of two variables belonging to some exponential weighted spaces. In Sec. 3.1 and 3.2 we give two theorems on the degree of approximation and two theorems of the Voronovskaya type. In Sec. 3.3 the Bernstein inequalities for these singular integrals are proved.Some similar results for the Picard and the Gauss-Weierstrass singular integral of functions of one variable were given in [1] - [3]

On the summability of numerical and orthogonal series by the (B,n)-method

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Approximation to continuous functions

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On the relation between the summability methods (С,α,β)(С, \alpha, \beta) and (A,m,n)(A, m, n) of double series

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On the equivalence of logarithmic methods of summabi lity of orthonormal series

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On some summability methods of the Abel type

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