Ukrainian Mathematical Journal

, Volume 64, Issue 7, pp 1090–1108 | Cite as

Exact order of approximation of periodic functions by one nonclassical method of summation of Fourier series

  • O. V. Kotova
  • R. M. Trigub
Article

By using an exact estimate for approximation by known trigonometric polynomials, we strengthen a Jackson-type theorem. Moreover, we determine the exact order of approximation of some periodic functions by these polynomials. For this purpose, we introduce a special modulus of smoothness.

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Copyright information

© Springer Science+Business Media New York 2012

Authors and Affiliations

  • O. V. Kotova
    • 1
  • R. M. Trigub
  1. 1.DonetskUkraine

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