A Note On Generalized $L_p$ Inequalities for the polar derivative of a polynomial

Abstract

Let \( P(z) \) be a polynomial of degree \( n \) and $\alpha \in \mathbb{C}$. The polar derivative of \( P(z) \), denoted by \( D_αP(z) \) and is defined by $D_{\alpha }P(z):=nP(z)+(\alpha -z)P^{\prime }(z)$. The polar derivative \( D_αP(z) \) is a polynomial of degree at most \( n - 1 \) and it generalizes the ordinary derivative \( P'(z) \). In this paper, we establish some \( L_p \) inequalities for the polar derivative of a polynomial with all its zeros located within a prescribed disk. Our results refine and generalize previously known findings.

6 pages