We obtain exact-order estimates for the best approximation of periodic functions of several variables from the classes \( MB_{{p,\theta }}^{\omega } \) by trigonometric polynomials with the “numbers” of harmonics from graded hyperbolic crosses in the metric of the space L q :
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Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 64, No. 1, pp. 140–144, January, 2012.
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Stasyuk, S.A. Best approximation of periodic functions of several variables from the classes \( MB_{{p,\theta }}^{\omega } \) . Ukr Math J 64, 156–161 (2012). https://doi.org/10.1007/s11253-012-0635-z
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DOI: https://doi.org/10.1007/s11253-012-0635-z