Interpolatory estimates for convex piecewise polynomial approximation

Kirill A. Kopotun, Dany Leviatan, Igor A. Shevchuk

In this paper, among other things, we show that, given $r\in N$, there is a constant $c=c(r)$ such that if $f\in C^r[-1,1]$ is convex, then there is a number ${\mathcal N}={\mathca…