On The Existence Of Periodic Solutions Of Certain Fourth OrderudDifferential Equations with Dealy

摘要

We derive existence results for theudperiodic boundary value problemud.r'" ' + uf.· + f (.); ).: + ex + g (f. r(..r - r) = p ( l )ud ( OJ = x(2rrl .. ~ (0) = .· (2 17' ) . . ' Ol = x! '21r ).ud:'' (0) i ' : ' (2 7r)udusing degree theoretic methods. The uniqueness ofudperiodic solutions is also examined