Certain Subclasses of Bi-Close-to-Convex Functions Associated with Quasi-Subordination

Abstract

In the present investigation, we introduce certain new subclasses of the class of biunivalent functions in the open unit disc defined by quasi-subordination. We obtained estimates on the initial coefficients $\left|a_{\mathrm{2}}\right|$ and $\left|a_{\mathrm{3}}\right|$ for the functions in these subclasses. The results present in this paper would generalize and improve those in related works of several earlier authors.