On the Sharpness of a Jackson Estimate b
✍
L. Imhof
📂
Article
📅
1996
🏛
Elsevier Science
🌐
English
⚖ 412 KB
Using ideas of Gru nwald, Marcinkiewicz, and Ve rtesi concerning the divergence of interpolation processes, a counterexample is constructed which establishes that a Jackson estimate for the best approximation by algebraic polynomials given by Ditzian and Totik is sharp in a pointwise sense everywher