“…Many mathematical models in science and engineering fields ( [3], [4], [5], [6], [7], [10], [13]) can be formulated in the form of linear and nonlinear ordinary differential equations ( [9], [12]) which need an analytical method ( [2], [15], [17]) to solve the exact equations. However in some problems, we cannot obtain the exact solutions by the analytical method in [7] for example y ′ = x 2 + y 2 .…”