### THE FEKETE-SZEGO PROBLEMS FOR SUBCLASS OF BI-UNIVALENT FUNCTIONS ASSOCIATED WITH SIGMOID FUNCTION

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#### 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 |a2| and |a3|, where a2, a3 are the initial Taylor-Maclaurin coefficients. Further we obtain the Fekete-Szego 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.

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DOI: https://doi.org/10.22190/FUMI201022034O

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