65 Years since the Paper “on the Value of the Best Approximation of Functions Having a Real Singular Point” by I. I. Ibragimov
نویسندگان
چکیده
In his famous paper [15] Ibragim Ibishievich Ibragimov has given asymptotic values of the best uniform approximation of functions of the form (a − x) ln(a − x), (a ≥ 1). These results have led to the development of a series of new directions in Approximation Theory, including the following ones, to which we devote this paper. • Constructive characterization of approximation of functions on a closed interval. • Babenko spaces. • Ditzian-Totik moduli of smoothness. • Constructive characterization of approximation of functions on the sets of complex plane. • Shape preserving approximation. In particular, we will show how we have applied the results by I. I. Ibragimov in our recent paper in the journal Constructive Approximation.
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