Raffoul, Youssef N.2021-01-272021-01-272003-10-06Raffoul, Y. N. (2003). Periodic solutions for neutral nonlinear differential equations with functional delay. <i>Electronic Journal of Differential Equations, 2003</i>(102), pp. 1-7.1072-6691https://hdl.handle.net/10877/13153We use Krasnoselskii's fixed point theorem to show that the nonlinear neutral differential equation with functional delay x'(t) = -α(t)x(t) + c(t)x' (t - g(t)) + q(t, x(t), x(t - g(t)) <p>has a periodic solution. Also, by transforming the problem to an integral equation we are able, using the contraction mapping principle, to show that the periodic solution is unique.Text7 pages1 file (.pdf)enAttribution 4.0 InternationalKrasnoselskiiNeutralNonlinearIntegral equationsPeriodic solutionsUnique solutionsArticle