The Calculus of Reverse Order of q-Analogue

This chapter is an introduction to a new type of analogue named Q -analogue for some operators. Here we have considered well-known operators named Baskakov Durrmeyer operators. This new type of analogue is considered as reverse order of q-analogue. In this chapter, we establish a direct approximation theorem, a weighted approximation theorem followed by the estimations of the rate of convergence of these new types of operators for functions of polynomial growth on the interval [0,∞).