Compare between least square method and petrov-galerkin method for solving the first order linear ordinary delay differential equations

الملخص EN

The problem of find approximate solution for the first order linear ordinary delay differential equations by using two of the special cases of the weighted residual method which are the least squares method and Petrov-Galerkin method with compare between these methods for which the best approximate solution near to the exact solution, also numerical applications are considered in this work.