Pointwise approximation by Baskakov quasi-interpolants

Recently, the quasi-interpolants of some classical operators were introduced. Mache and Müller gave Baskakov quasi-interpolants and obtained approximation equivalence theorem with ωϕ2r(f,t)∞ In this paper, we extend the above result with modulus ωϕλ2r(f,t)∞ (0 ≤ λ ≤ 1) which unified classical modulus and Ditzian-Totik modulus.