Tunç, C.2025-05-102025-05-1020111024-76962-s2.0-79960776327https://hdl.handle.net/20.500.14720/18238A kind of seventh order nonlinear delay differential equations is con-sidered. By using the Lyapunov-Krasovskii functional approach [5], some sufficient conditions are established which guarantee that the zero solution of the equation considered is unstable. Our conditions are new and supplement previously known results. © Cemil Tunç, 2011.eninfo:eu-repo/semantics/closedAccessDelay Differential EquationInstabilityLyapunov-Krasovskii FunctionalSeventh OrderArticle