Semnan UniversityInternational Journal of Nonlinear Analysis and Applications2008-68229120180801Fekete-Szeg"o problems for analytic functions in the space of logistic sigmoid functions based on quasi-subordination5568308210.22075/ijnaa.2018.11778.1589ENMurugusundaramoorthyGangadharanDr. G. Murugusundaramoorthy, Ph.D.
Sr.Professor of Mathematics,
School of Advanced Sciences,
VIT University, Vellore 632 014
India ,www.vit.ac.in0000-0001-8285-6619Sunday OluwafemiOlatunjiDepartment 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 <span>subclasses</span> <span>${S}^{*}_{q}(alpha,Phi),$</span> <span>${M}_{q}(alpha,Phi)$</span> and <span>${L}_{q}(alpha,Phi)$</span> of analytic functions in the space of logistic <span>sigmoid</span> functions based on quasi--subordination and determine the initial coefficient estimates <span>$|a_2|$</span> and <span>$|a_3|$</span> and also determine the relevant connection to the classical <span>Fekete</span>--<span>Szeg</span><span>"</span>o inequalities. Further, we discuss the improved results for the associated classes involving subordination and <span>majorization</span> results briefly.https://ijnaa.semnan.ac.ir/article_3082_32c7c0a2eb966732ef665b9730390061.pdf