抄録
Numerical solution of ordinary differential equations usually applies the fourth order precision Runge-Kutta method, and it is common to find a solution by this finite difference approximation. As for the analytic solutions, many books are published recently. However, there are not so many documents for the numerical solutions. Here, we show some exercises and show the program of the C language. Based on these results, we want to discuss them about some problems and the future prospects.
