Certain Subclasses of Bistarlike and Biconvex Functions Based on Quasi-Subordination

Abstract

We introduce the unified biunivalent function class ${\mathcal{M}}_{q,\sigma }^{\delta ,\lambda }(\gamma ,\phi )$ defined based on quasi-subordination and obtained the coefficient estimates for Taylor-Maclaurin coefficients $|a_{\mathrm{2}}|$ and $|a_{\mathrm{3}}|$. Several related classes of functions are also considered and connections to earlier known and new results are established.