Approximation by Double Deferred Nörlund Means of Double Fourier Series for Lipschitz Functions
Abstract
In this paper, the concept of Double Deferred Nörlund means is defined
and some important results are obtained. Particularly, we investigate the rate
of uniform approximation by Double Deferred Nörlund means of the rectangular
partial sums of the double Fourier series of a function belong to on the two dimensional
region . We also obtain the rate of uniform approximation by Double
Deferred Cesáro means.
Keywords
Functions of bounded variation,Ostrowski type inequalities,Riemann-Stieltjes integrals
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