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On the Best Polynomial Approximations of $2π$-Periodic Functions and Exact Values of $n$-Widths of Functional Classes in the Space $L_2$

To solve extremal problems of approximation theory in the space $L_2$, we use τ-moduli introduced by Ivanov. We determine the exact values of constants in Jackson-type inequalities and the exact values of $n$-widths of functional classes determined by these moduli.

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Bibliographic Details
Date:	2002
Main Authors:	Vakarchuk, S. B., Вакарчук, С. Б.
Format:	Article
Language:	Russian English
Published:	Institute of Mathematics, NAS of Ukraine 2002
Online Access:	https://umj.imath.kiev.ua/index.php/umj/article/view/4199
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Journal Title:	Ukrains’kyi Matematychnyi Zhurnal
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