Fekete–Szegö coefficient functional for quasi-subordination class

Abstract

In the present paper, we introduce a certain subclass of analytic univalent functions which is defined in terms of a quasi-subordination and we obtain certain sharp bounds of the Fekete–Szego functional for functions belonging to this class. The results presented give improved versions for this and associated classes involving the subordination and majorization. Special cases of the main results are also mentioned briefly.