Some Results on Post-Widder Operators Preserving Test Function x^r

Abstract

In the present paper, we consider Post-Widder operators and its modified form which preserve the test function xr, r ∈ ℕ. We estimate direct results in terms of modulus of continuity for the modified operators. Also, some estimates for polynomially bounded functions and linear combinations are considered. Our estimates improve in some sense the previous results for the original Post-Widder operators.