Glasnik Matematicki, Vol. 40, No.1 (2005), 133-138.

A REMARK ON CONCENTRATION OF THE ERROR BETWEEN A FUNCTION AND ITS BEST POLYNOMIAL APPROXIMANTS. II: A PROBLEM OF HASSON

J. L. Wang and S. P. Zhou

Department of Mathematics, Shaoxing Arts and Science College, Shaoxing, Zhejiang 312000, China

Institute of Mathematics, Zhejiang University of Sciences, Xiasha Economic Development Area, Hangzhou, Zhejiang 310018, China
e-mail: szhou@nbip.net
e-mail: szhou@zjip.com


Abstract.   In the present paper we construct a function to give a positive answer to a problem raised by Hasson, that says, the conclusion of a result cannot be strengthened.

2000 Mathematics Subject Classification.   41A17, 41A25, 41A50.

Key words and phrases.   Approximation, construction, Chebyshev polynomial.


Full text (PDF) (free access)

DOI: 10.3336/gm.40.1.12


References:

  1. N.I. Akhiezer, Theory of Approximation, Ungar, New York, 1956.

  2. G. Freud, Eine Ungleichung für Tschebyscheffsche Approximations-polynome, Acta Sci. Math. 19 (1958), 162-164.

  3. M. Ganzburg, Moduli of smoothness and best approximation of functions with singularities, Computers & Mathematics 40 (2000), 219-242.

  4. M. Hasson, Concentration of the error between a function and its polynomial of best uniform approximation, Proc. Edinburgh Math. Soc. 41 (1998), 447-463.

  5. S. B. Stechkin, On the order of the best approximations of continuous functions, Izv. Akad. Nauk SSSR 15 (1951), 219-242 (in Russian).

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