Approximation by a new generalization of Szász-Mirakjan operators via (p,q )-calculus

In this work, we obtain the approximation properties of a new generalization of Szász-Mirakjan operators based on postquantum calculus. Firstly, for these operators, a recurrence formulation for the moments is obtained, and up to the fourth degree, the central moments are examined. Then, a local approximation result is attained. Furthermore, the degree of approximation in respect of the modulus of continuity on a finite closed set and the class of Lipschitz are computed. Next, the weighted uniform approximation on an unbounded interval is showed, and by the modulus of continuity, the order of convergence is estimated. Lastly, we proved the Voronovskaya type theorem and gave some illustrations to compare the related operators’ convergence to a certain function.