Sigmoid function in the space of univalent λ-pseudo starlike functions

Abstract

In the present investigation, we obtain initial coefficients of λ- pseudo starlike functions related to sigmoid functions and the Fekete-Szegöcoefficient functional |a3 - μa22| for certain normalized analytic functions defined on the open unit disk. As an application of the main result,we pointed out the initial coefficients and Fekete-Szegö inequality for a subclasses of starlike functions related to sigmoid functions.