Global approximation by Szasz-Durrmeyer operators

In this thesis, the apparoximation properties of the sequences of Szasz-Durrmeyer operators are investigated on any finite closed interval of and on the weighted spaces of integrable continuous functions defined on , having polynomial growthy. Some estimates are given related to the rate of convergence of the operators for continuous functions in the and spaces. Furtermore, by the modified operator preserving the test function we get a better error estimation.