On directional Whitney inequality

Feng Dai, Andriy Prymak

This paper studies a new Whitney type inequality on a compact domain $\Omega \subset {\mathbb{R}}^d$ that takes the form $$\inf_{Q\in Π_{r-1}^d({\mathcal{E}})} \|f-Q\|_p \leq C(p,r,Ω) ω_…