Inequalities for the polar derivative of a polynomial

Let P(z) be a polynomial of degree n having all its zeros in vertical bar z vertical bar <= 1, then according to Turan (Compositio Mathematica 7:89-95, 2004) max(vertical bar Z vertical bar=1) vertical bar P'(z)vertical bar >= n/2(max vertical bar Z vertical bar=1) vertical bar P(z)vertical bar. In this paper, we shall use polar derivative and establish a generalisation and an extension of this result. Our results also generalize variety of other results.