中文说明：资源描述建立微分方程只是解决问题的第一步，通常需要求出方程的解来说明实际现象，并 加以检验。如果能得到解析形式的解固然是便于分析和应用的，但是我们知道，只有线 性常系数微分方程，并且自由项是某些特殊类型的函数时，才可以得到这样的解，而绝 大多数变系数方程、非线性方程都是所谓“解不出来”的，即使看起来非常简单的方程 如 y2 x2 dx dy = + 。于是对于用微分方程解决实际问题来说，数值解法就是一个十分重 要的手段。
English Description：
Application backgroundThe establishment of differential equations is the first step to solve the problem.Test. If we can get the solution of the analytical form is convenient for analysis and application, but we know that only the lineOrdinary differential equations with constant coefficients, and the free term is a function of certain special types, which can be obtained by such a solution.Most of the variable coefficient equations and nonlinear equations are called "solutions", even though it seems very simple.Such as x2 Y2DXDy = +. As a result, the numerical solution is a very important problem for solving the practical problems.Means of.