Reliable analysis for delay differential equations arising in mathematical biology

In this study, delay differential equations are investigated using the variational iteration method. Delay differential equations (DDEs) have a wide range of application in science and engineering. They arise when the rate of change of a time-dependent process in its mathematical modeling is not only determined by its present state but also by a certain past state. Recent studies in such diverse fields as biology, economy, control and electrodynamics have shown that DDEs play an important role in explaining many different phenomena. The procedure of present method is based on the search for a solution in the form of a series with easily computed components. Some numerical illustrations are given. These results reveal that the proposed method is very effective and simple to perform.