On the approximation of bounded functions by trigonometric polynomials in Hausdorff metric
Autor: | Sadekova, Ekaterina H. |
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Jazyk: | English<br />Russian |
Rok vydání: | 2023 |
Předmět: | |
Zdroj: | Известия Саратовского университета. Новая серия. Серия Математика. Механика. Информатика, Vol 23, Iss 2, Pp 169-182 (2023) |
Druh dokumentu: | article |
ISSN: | 1816-9791 2541-9005 |
DOI: | 10.18500/1816-9791-2023-23-2-169-182 |
Popis: | The article discusses a method for constructing a spline function to obtain estimates that are exact in order to approximate bounded functions by trigonometric polynomials in the Hausdorff metric. The introduction provides a brief history of approximation of continuous and bounded functions in the uniform metric and the Hausdorff metric. Section 1 contains the main definitions, necessary facts, and formulates the main result. An estimate for the indicated approximations is obtained from Jackson's inequality for uniform approximations. In section 2 auxiliary statements are proved. So, for an arbitrary $2\pi$-periodic bounded function, a spline function is constructed. Then, estimates are obtained for the best approximation, variation, and modulus of continuity of a given spline function. Section 3 contains evidence of the main results and final comments. |
Databáze: | Directory of Open Access Journals |
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