English

Inequalities of the Hermite-Hadamard type involving numerical differentiation formulas

Classical Analysis and ODEs 2014-12-01 v1

Abstract

We observe that the Hermite-Hadamard inequality written in the form f(x+y2)F(y)F(x)yxf(x)+f(y)2f\left(\frac{x+y}{2}\right)\leq\frac{F(y)-F(x)}{y-x}\leq\frac{f(x)+f(y)}{2} may be viewed as an inequality between two quadrature operators f(x+y2)f\left(\frac{x+y}{2}\right) f(x)+f(y)2\frac{f(x)+f(y)}{2} and a differentiation formula F(y)F(x)yx.\frac{F(y)-F(x)}{y-x}. We extend this inequality, replacing the middle term by more complicated ones. As it turns out in some cases it suffices to use Ohlin lemma as it was done in a recent paper \cite{Rajba} however to get more interesting result some more general tool must be used. To this end we use Levin-Ste\v{c}kin theorem which provides necessary and sufficient conditions under which inequalities of the type we consider are satisfied.

Keywords

Cite

@article{arxiv.1411.7859,
  title  = {Inequalities of the Hermite-Hadamard type involving numerical differentiation formulas},
  author = {Andrzej Olbryś and Tomasz Szostok},
  journal= {arXiv preprint arXiv:1411.7859},
  year   = {2014}
}