The generalization of certain results for Szasz-Mirakjan-Schurer operators

The present article continues earlier research by authors, in order to reach two goals. Firstly, we give a general formula concerning calculation of the test functions by Szasz-Mirakjan-Schurer operators and secondly, we establish a Voronovskaja type theorem, the uniform convergence and the order of approximation using the modulus of continuity for the same operators.