Results 21 to 30 of about 74 (69)
Stečkin inequalities for summability methods
International Journal of Mathematics and Mathematical Sciences, Volume 20, Issue 1, Page 93-100, 1997., 1995 Stečkin proved an inequality on Fejér means of Fourier series He said, “Proving similar inequality for other summability method is an interesting problem.” We generalize Stečkin′s inequality and give various applications to summability methods.
Jia-Ding Cao
wiley +1 more source
A pointwise approximation theorem for linear combinations of Bernstein polynomials
Abstract and Applied Analysis, Volume 1, Issue 4, Page 397-406, 1996., 1996 Recently, Z. Ditzian gave an interesting direct estimate for Bernstein polynomials. In this paper we give direct and inverse results of this type for linear combinations of Bernstein polynomials.
Shunsheng Guo +4 more
wiley +1 more source
Properties of the modulus of continuity for monotonous convex functions and applications
International Journal of Mathematics and Mathematical Sciences, Volume 18, Issue 3, Page 443-446, 1995., 1992 For a monotone convex function f ∈ C[a, b] we prove that the modulus of continuity w(f; h) is concave on [a, b] as function of h. Applications to approximation theory are obtained.
Sorin Gheorghe Gal
wiley +1 more source
Finite‐infinite range inequalities in the complex plane
International Journal of Mathematics and Mathematical Sciences, Volume 14, Issue 4, Page 625-638, 1991., 1991 Let E⫅C be closed, ω be a suitable weight function on E, σ be a positive Borel measure on E. We discuss the conditions on ω and σ which ensure the existence of a fixed compact subset K of E with the following property. For any p, 0 < P ≤ ∞, there exist positive constants c1, c2 depending only on E, ω, σ and p such that for every integer n ≥ 1 and every
H. N. Mhaskar
wiley +1 more source
The first Zolotarev case in the Erdös-Szegö solution to a Markov-type extremal problem of Schur [PDF]
, 2017 Schur’s [14] Markov-type extremal problem asks to find the maximum (1) (2) (1) sup sup |Pn (ξ)|, where Bn,ξ,2 = {Pn ∈ Bn : Pn (ξ) = 0} ⊂ Bn =−1≤ξ≤1 Pn ∈Bn,ξ,2 {Pn : |Pn(x)| ≤ 1 for |x| ≤ 1} and Pn is an algebraic polynomial of degree ≤ n.
RACK, Heinz-Joachim
core +2 more sources
Kernels and best approximations related to the system of ultraspherical polynomials [PDF]
, 2005 22 pages, no figures.-- MSC2000 codes: 41A10; 41A17; 41A25; 42C10; 33C45.MR#: MR2129477 (2005k:41087)Zbl#: Zbl 1074.41003We study the uniformly bounded orthonormal system $ \Cal U_\lambda $ of functions $$ u_n (\lambda )}(x)=\varphi _n (\lambda )}(\cos x)
Marcellán, Francisco +4 more
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On global smoothness preservation by Bernstein-type operators [PDF]
, 2015 We study global smoothness preservation of a function f by sequences of Bernstein-type operators with respect to a certain modulus of continuity of order two.
TALPĂU DIMITRIU, Maria
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Principles of Extremum and Application to some Problems of Analysis [PDF]
, 1998 AMS subject classification: 41A17, 41A50, 49Kxx, 90C25.The aim of this paper is to demonstrate applications of a direct approach to the solution of extremal problems to some concrete problems of classical analysis, calculus of variations and ...
Tikhomirov, V.
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Quantitative results for the convergence of the iterates of some King type operators
, 2019 In this article we construct three q -King type operators which fix the functions e0 and e2 +αe1, α > 0. We study the rates of convergence for the iterates of these operators using the first and the second order modulus of continuity. We show that the
BIROU, Marius Mihai
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Letter to the Editor. Remarks on Some Inequalities for Polynomials [PDF]
, 2013 MSC 2010: 30A10, 30C10, 30C80, 30D15, 41A17.In the present article, I point out serious errors in a paper published in Mathematica Balkanica three years ago. These errors seem to go unnoticed because some mathematicians are applying the results stated in
Hachani, M. A.
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