Coefficient Estimates in New Subclasses of Analytic and Bi-Univalent Functions Defined by the Combinations of the <i>q</i>-derivative and the Sălăgean Derivative Operator
We introduce and study two new subclasses of the function class Sigma of bi-univalent functions defined in the open unit disk and associated with the S & abreve;l & abreve;gean and q-derivative operators. Furthermore, we find estimates for the Taylor-Maclaurin coefficients a2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\left|{a}_{2}\right|$$\end{document} and a3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\left|{a}_{3}\right|$$\end{document} of the functions from these new subclasses. The accumulated results are quite interesting and new.
- Journal
- UKRAINIAN MATHEMATICAL JOURNAL
- Year
- 2026
- Volume
- 78
- Issue
- 2
- ISSN
- 0041-5995
- eISSN
- 1573-9376
- DOI
- 10.1007/s11253-026-02558-9
- WoS UID
- WOS:001721706900004