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𝒜-summability and approximation of continuous periodic functions. (English) Zbl 1199.41137
The paper is concerned with sequences of positive linear operators defined on the space of real-valued continuous 2π-periodic functions. The author gives a generalization of the classical Korovkin theorem (with 1, cosx and sinx as test functions) by using a matrix summability method.
MSC:
41A36Approximation by positive operators
47B38Operators on function spaces (general)