Inverse theorem for best polynomial approximation in

Authors:
Z. Ditzian, D. Jiang and D. Leviatan

Journal:
Proc. Amer. Math. Soc. **120** (1994), 151-155

MSC:
Primary 41A25; Secondary 41A10, 41A17, 41A27

DOI:
https://doi.org/10.1090/S0002-9939-1994-1160297-7

MathSciNet review:
1160297

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Abstract | References | Similar Articles | Additional Information

Abstract: A direct theorem for best polynomial approximation of a function in , has recently been established. Here we present a matching inverse theorem. In particular, we obtain as a corollary the equivalence for between and . The present result complements the known direct and inverse theorem for best polynomial approximation in . Analogous results for approximating periodic functions by trigonometric polynomials in , are known.

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Additional Information

DOI:
https://doi.org/10.1090/S0002-9939-1994-1160297-7

Keywords:
Inverse theorems,
best polynomial approximation,
spaces,

Article copyright:
© Copyright 1994
American Mathematical Society