APPROXIMATION OF BIVARIATE FUNCTIONS BY OPERATORS OF STANCU-HURWITZ TYPE

The aim of this paper is to introduce and study a linear positive approximation operator of Stancu-Hurwitz type [1], depending on several non negative parameters, useful in the approximation of functions of two variables. The corresponding approximation formula (3.1) has the degree of exactness (1, 1). For the remainder of this formula we give several representations, by starting from a method of T. Popoviciu [7] for representation of the remainder term in linear approximation formulas, by using the divided differences.