A characterization of weighted approximations by the Post–Widder and the Gamma operators, II Original Research Article

We present a characterization of the approximation errors of the Post–Widder and the Gamma operators in View the MathML sourceLp(0,∞),1≤p≤∞, with a weight xγ0(1+x)γ∞−γ0xγ0(1+x)γ∞−γ0 with arbitrary real γ0,γ∞γ0,γ∞. Characteristics of two types are used — weighted KK-functionals of the approximated function itself and the classical fixed-step moduli of smoothness taken on simple modifications of it.