الفهرس | Only 14 pages are availabe for public view |
Abstract The objective of this dissertation is to study the stability, boundedness, asymptotic behaviour and periodicity of solutions for some scalar and vector non-linear ordinary differential equations of the fourth and fifth-order. We present some concepts and methods of the qualitative theory of ordinary differential equations, which are needed for the study of stability and boundedness of the solutions of certain non-linear differential equations . also we introduce some theorems concerning the exis tevce of periodic solutions of non-autonomous differential systems. |