Use of identity of A. Hurwitz for construction of a linear positive operator of approximation

By using a general algebraic identity of Adolf Hurwitz [1], which generalizes an important identity of Abel, we construct a new operator \(S_m^{(\beta_1,\ldots,\beta_m)}\) approximating the functions. A special case of this is the operator \(Q_m^\beta\) of Cheney-Sharma. We show that this new opera...

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Bibliographic Details
Main Author: Dimitrie D. Stancu
Format: Article
Language:English
Published: Publishing House of the Romanian Academy 2002-02-01
Series:Journal of Numerical Analysis and Approximation Theory
Subjects:
Online Access:https://ictp.acad.ro/jnaat/journal/article/view/714
Description
Summary:By using a general algebraic identity of Adolf Hurwitz [1], which generalizes an important identity of Abel, we construct a new operator \(S_m^{(\beta_1,\ldots,\beta_m)}\) approximating the functions. A special case of this is the operator \(Q_m^\beta\) of Cheney-Sharma. We show that this new operator, applied to a function \(f\in C[0,1]\), is interpolatory at both sides of the interval \([0,1]\), and reproduces the linear functions. We also give an integral representation of the remainder of the approximation formula of the function \(f\) by means of this operator. By applying a criterion of T. Popoviciu [2], is also given an expression of this remainder by means of divided difference of second order.
ISSN:2457-6794
2501-059X