Tunc, Cemil2025-05-102025-05-1020110354-518010.2298/FIL1103145T2-s2.0-79960778941https://doi.org/10.2298/FIL1103145Thttps://hdl.handle.net/20.500.14720/11556Tunc, Cemil/0000-0003-2909-8753Text of the abstract. The main purpose of this paper is to introduce a new instability theorem related to a fifth order nonlinear differential equation with a constant delay. By means of the Lyapunov-Krasovskii ([8], [13]) functional approach, we obtain a new result on the topic.eninfo:eu-repo/semantics/openAccessInstabilityLyapunov-Krasovskii FunctionalDelay Differential EquationFifth OrderArticle