We consider the deviations of Fourier sums in the spaces \( {C^{\bar{\psi}}} \). The estimates of these deviations are expressed via the best approximations of the \( \bar{\psi} \) -derivatives of functions in the Stepanets sense. The sequences \( \bar{\psi} \) = (ψ1, ψ2) are quasiconvex.
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Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 65, No. 6, pp. 844–849, June, 2013.
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Zaderei, N.M., Zaderei, P.V. On the Lebesgue Inequality on Classes of \( \bar{\psi} \) -Differentiable Functions. Ukr Math J 65, 938–944 (2013). https://doi.org/10.1007/s11253-013-0830-6
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DOI: https://doi.org/10.1007/s11253-013-0830-6