q-Voronovskaya type theorems for q-Baskakov operators

In the present paper, we prove quantitative q-Voronovskaya type theorems for q-Baskakov operators in terms of weighted modulus of continuity. We also present a new form of Voronovskaya theorem, that is, q-Grüss-Voronovskaya type theorem for q-Baskakov operators in quantitative mean. Hence, we describe the rate of convergence and upper bound for the error of approximation, simultaneously. Our results are valid for the subspace of continuous functions although classical ones is valid for differentiable functions. Copyright © 2015 John Wiley & Sons, Ltd.