Korovkin type criterion for some Voronovskaja type formulae
Dedicated to Professor Gheorghe Coman on his 90th anniversary
DOI:
https://doi.org/10.24193/subbmath.2026.3.7Keywords:
Positive linear operators, Voronovskaja type formulae, criterion, test functionsAbstract
In this note we present a simple criterion to validate some Voronovskaja type formulae. We show that it is sufficient to check the validity of the Voronovskaja formula on the test functions φi, i = 0, ..., 4, where φ is a function satisfying some conditions, to get the validity for the general case.
Mathematics Subject Classification (2010): 41A36, 41A25, 41A10.
Received 04 April 2026; Accepted 15 May 2026.
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