This example attempts to show to both teachers and users of mathematics how, as a result of studying a practical problem, two areas of applied mathematics which are usually unrelated are nicely combined to produce a solution of the problem. Further, it is suggested that the derived solution is probably easier to handle than one obtained by other more conventional methods. The two areas which are related are differential equations and recurrence relations. Even so, it is interesting and useful from the teaching point of view to compare and contrast the three methods outlined in the paper.