Abstract
Let the set of generalized polynomials having bounded coefficients beK={p=\(\mathop \Sigma \limits_{j = 1}^n \) α jgj.α j≤α j≤β j,j=1, 2, ...,n}, whereg 1,g 2, ...,g n are linearly independent continuous functions defined on the interval [a, b],α j,β j are extended real numbers satisfyingα j<+∞,β j>-∞, andα j≤β j. Assume thatf is a continuous function defined on a compact setX ⊂ [a, b]. This paper gives the characterization theorem forp being the best uniform approximation tof fromK, and points out that the characterization theorem can be applied in calculating the approximate solution of best approximation tof fromK.
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References
Shi Ying-guang, Uniform Approximation by Generalized Polynomials Having Bounded Coefficients,Acta Math. Appl. Sinica,5 (1982), 353–356.
Roulier, J. A., & Taylar, G. D., Uniform Approximation by Polynomials Having Bounded Coefficients,Abh. Math. Sem. Univ. Hamburg,36 (1971), 126–135.
Karlin, S., & Studden, W. J., Tchebycheff Systems: with Applications in Analysis and Statistics, Interscience, New York, 1966.
Passow, E., Polynomials with Positive Coefficients: Uniqueness of Best Approximation,J. Approx. Theory,21 (1977), 352–355.
Cheney, E. W., Introduction to Approximation Theory, McGraw-Hill, New York, 1966.
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Xu, S. Characterization theorem of generalized polynomial of best approximation having bounded coefficients. Acta Mathematicae Applicatae Sinica 5, 361–366 (1989). https://doi.org/10.1007/BF02005957
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DOI: https://doi.org/10.1007/BF02005957