Radu, Cristina \(\mathcal A\)-summability and approximation of continuous periodic functions. (English) Zbl 1199.41137 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 PDF BibTeX XML Cite \textit{C. Radu}, Stud. Univ. Babeș-Bolyai, Math. 52, No. 4, 155--162 (2007; Zbl 1199.41137) OpenURL