Abstract
We prove that, for comonotone approximation, an analog of the second Jackson inequality with generalized Ditzian-Totik modulus of continuity ω ϕ k, r is not true for (k, r) = (2, 2) even in the case where the constant depends on a function.
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Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 57, No. 10, pp. 1424–1429, October, 2005.
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Nesterenko, O.N., Petrova, T.O. On one problem for comonotone approximation. Ukr Math J 57, 1667–1673 (2005). https://doi.org/10.1007/s11253-006-0021-9
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DOI: https://doi.org/10.1007/s11253-006-0021-9