Semnan UniversityInternational Journal of Nonlinear Analysis and Applications2008-68229120180901Fekete-Szeg\"o problems for analytic functions in the space of logistic sigmoid functions based on quasi-subordination5568308210.22075/ijnaa.2018.11778.1589ENMurugusundaramoorthy GangadharanDr. G. Murugusundaramoorthy, Ph.D.
Sr.Professor of Mathematics,
School of Advanced Sciences,
VIT University, Vellore 632 014
India0000-0001-8285-6619Sunday Oluwafemi OlatunjiDepartment of Mathematical Sciences, Federal University of Technology, Akure, NigeriaO.A. Fadipe-JosephDepartment of Mathematics, University of Ilorin, P.M.B. 1515 Ilorin, Nigeria0000-0001-7781-6807Journal Article20170628In this paper, we define new subclasses ${S}^{*}_{q}(\alpha,\Phi),$ ${M}_{q}(\alpha,\Phi)$ and ${L}_{q}(\alpha,\Phi)$ of analytic functions in the space of logistic sigmoid functions based on quasi--subordination and determine the initial coefficient estimates $|a_2|$ and $|a_3|$ and also determine the relevant connection to the classical Fekete-Szego inequalities. Further, we discuss the improved results for the associated classes involving subordination and majorization results briefly.https://ijnaa.semnan.ac.ir/article_3082_32c7c0a2eb966732ef665b9730390061.pdf