Open Access Research

On q-analogue of a complex summation-integral type operators in compact disks

Ravi P Agarwal1 and Vijay Gupta2*

Author Affiliations

1 Department of Mathematics, Texas A&M University-Kingsville, 700 University Blvd., Kingsville, TX 78363-8202, USA

2 School of Applied Sciences, Netaji Subhas Institute of Technology, Sector 3 Dwarka, New Delhi-110078, India

For all author emails, please log on.

Journal of Inequalities and Applications 2012, 2012:111 doi:10.1186/1029-242X-2012-111

Published: 22 May 2012

Abstract

Recently, Gupta and Wang introduced certain q-Durrmeyer type operators of real variable x ∈ [0, 1] and studied some approximation results in the case of real variables. Here we extend this study to the complex variable for analytic functions in compact disks. We establish the quantitative Voronovskaja type estimate. In this way, we put in evidence the over convergence phenomenon for these q-Durrmeyer polynomials; namely, the extensions of approximation properties (with quantitative estimates) from the real interval [0,1] to compact disks in the complex plane. Some of these results for q = 1 were recently established in Gupta-Yadav.

Mathematical subject classification (2000): 30E10; 41A25.

Keywords:
Complex q-Durrmeyer operators; q-integer; q-factorial; q-Beta function; exact order of approximation; quantitative Voronovskaja-type asymptotic formula