The Fekete-Szego Problems for Subclass of Bi-Univalent Functions Associated with Sigmoid Function

Abstract

The purpose of this article is to introduce a new subclass of analytic and bi-univalent functions, in associated with sigmoid function and to investigate the upper bounds for |a(2)| and |a(3)|, where a(2), a(3) are the initial Taylor-Maclaurin coefficients. Further, we obtain the Fekete-Szego 5 inequalities for this subclass of the bi-univalent function class sigma. We also give several illustrative examples of the bi-univalent function class which we introduce here.