2 papers
math.CA2017
Interpolatory pointwise estimates for monotone polynomial approximation
K. A. Kopotun, D. Leviatan, I. A. Shevchuk
Given a nondecreasing function on , we investigate how well it can be approximated by nondecreasing algebraic polynomials that interpolate it at . We establish p…
math.CA2017
On weighted approximation with Jacobi weights
Kirill A. Kopotun, Dany Leviatan, Igor A. Shevchuk
We obtain matching direct and inverse theorems for the degree of weighted -approximation by polynomials with the Jacobi weights . Combined, the estimates yield…