The generalization of some results for Bernstein and Stancu operators

In the present paper, we generalize some results for Bernstein and Stancu operators. Firstly, we establish a relationship between two results concerning the calculation of test functions by Bernstein operators. Secondly, using this relationship and some known results we prove in every case a Voronovskaja type theorem, the uniform convergence and the order of approximation for Bernstein and Stancu operators.