Coefficient Estimates for Two New Subclass of Bi-Univalent Functions Defined by Cosine and Logarithmic Functions. Coefficient Estimates for two new Subclass

This study proposes two novel subclasses of analytic and bi-univalent functions constructed using cosine and logarithmic functions. The primary aim is to establish sharp estimates for the initial coefficients in their Taylor--Maclaurin series. Furthermore, the Fekete-Szegö inequality is investigated for functions within these subclasses and Several corollaries are obtained by assigning specific values to the associated parameters. These results contribute to the advancement of geometric function theory and provide a basis for future research in related function classes.