This paper aims to study two approximate analytical methods for solving linear and nonlinear delay differential equations. Approximate approaches are shown in the Variational iteration method and the Adomian decomposition method. Through the conversion of some instances, including linear and nonlinear delay differential equations with initial values, by comparing different approximate methods. The results show that this procedure is accurate and adequate for DDE. Comparisons between the Adomian Decomposition Method and Variational Iteration Method results demonstrate the accuracy of the results obtained from both mentioned methods. The variational iteration method is efficient and convenient based on comparing the results and exact solutions.
Adomian Decomposition Method, Variational iteration method, Delay differential equations, Initial value problem, Exact solution