Caglar, MuratCotirla, Luminita-IoanaBuyankara, Mucahit2026-03-262026-03-2620222073-899410.3390/sym140815722-s2.0-85137363017https://doi.org/10.3390/sym14081572https://hdl.handle.net/20.500.14901/1848Çağlar, Murat/0000-0001-8147-0343; Buyankara, Mucahit/0000-0003-2683-9229; Luminita-Ioana, Cotirla/0000-0002-0269-0688We introduce and investigate in this paper a new subclass of bi-univalent functions associated with the Gegenbauer polynomials which satisfy subordination conditions defined in a symmetric domain, which is the open unit disc. For this new subclass, we obtain estimates for the Taylor-Maclaurin coefficients vertical bar a(2)vertical bar, vertical bar a(3)vertical bar and the Fekete-Szego inequality vertical bar a(3)-mu a(2)(2)vertical bar.eninfo:eu-repo/semantics/openAccessGegenbauer PolynomialSubordinationBi-Univalent FunctionsAnalytic FunctionsFekete-Szego ProblemArticle