\(\mathcal A\)-summability and approximation of continuous periodic functions. (English) Zbl 1199.41137

Radu, Cristina

Stud. Univ. Babeș-Bolyai, Math. 52, No. 4, 155-162 (2007).

The paper is concerned with sequences of positive linear operators defined on the space of real-valued continuous \(2\pi\)-periodic functions. The author gives a generalization of the classical Korovkin theorem (with 1, \(\cos x\) and \(\sin x\) as test functions) by using a matrix summability method.

Reviewer: Ioan Rasa (Cluj-Napoca)

MSC:

41A36	Approximation by positive operators
47B38	Linear operators on function spaces (general)

Keywords:

matrix summability; Korovkin type theorem