ملخص
Abstract
In this thesis, we study different numerical methods used to solve ordinary differential equations of the first and second orders and where related important definitions are given . We will concentrate first on Differential Equations of the first order and the truncation errors which are derived for various methods and those compared with the expected errors , whenever possible . Two applications were given in science of biology and physics which were studied in details . Finally we draw our attention to ordinary differential equations of the second order where we study initial-value problems and boundary-value problems with the application of the wellknown numerical procedures :the shooting method and the finite difference method . The important conclusion we came up with is that the truncation error is always greater than the expected error for all methods used, and this which was expected .