DIRECT AND INVERSE APPROXIMATION THEOREMS WITH JACOBI WEIGHT AND DERIVATIVES OF BASKAKOV OPERATORS
Xue Yin-chuan · Chinese Annals of Mathematics,series A · 2005
Using the moduli of smoothness w (?)λ 2 (f, t)w, direct and inverse approximation theorems with Jacobi weight of Baskakov operators is established; And the relation between derivatives of the operators and the smoothness of functions to be approximated is obtained.