On H3(1) Hankel determinant for some classes of univalent function

Abstract

Focus in this paper is on the Hankel determinant H_3 (1) for the well known classes of bounded turning, starlike and convex functions in the open unit disk E={z∈ C:|z|<1}. The results obtained complete the series of research works in the search for sharp upper bounds in H_3 (1) for each of these classes