Second Hankel determinant problem for a certain subclass of univalent functions

Abstract

Let S denote the class of analytic and univalent functions in the open unit disk D = {z : |z| < 1} with the normalization conditions. In the present artical an upper bound for the second Hankel determinant |a<inf>2</inf>a<inf>4</inf> - a2<inf>3</inf>| is obtained for a certain subclass of univalent functions. © 2015 Elsevier B.V., All rights reserved.