中文说明：资源描述程序源码 常微分方程。自然科学与工程技术中种种运动发展过程与平衡现象各自遵守一定的规律。这些规律的定量表述一般地呈现为关于含有未知函数及其导数的方程。我们将只含有未知多元函数及其偏导数的方程，称之为偏微分方程。 方程中出现的未知函数偏导数的最高阶数称为偏微分方程的阶。如果方程中对于未知函数和它的所有偏导数都是线性的，这样的方程称为线性偏微分方程，否则称它为非线性偏微分方程。 初始条件和边界条件称为定解条件，未附加定解条件的偏微分方程称为泛定方程。对于一个具体的问题，定解条件与泛定方程总是同时提出。定解条件与泛定方程作为一个整体，称为定解问题。
English Description：
Application backgroundProgram source ordinary differential equations. Natural science and engineering technology in the development of various sports development process and the balance of the phenomenon of their compliance with certain laws. The quantitative expression of these rules is generally presented as an equation with the unknown function and its derivative. We will only have an equation with the unknown function and its partial derivatives, which is called the partial differential equation.The highest order of the partial derivative of the unknown function is called the order of partial differential equation. If the unknown function and its partial derivatives are linear, the equation is called a linear partial differential equation, which is called a nonlinear partial differential equation.The initial conditions and boundary conditions are called the set of solutions, and the partial differential equations of the condition of the non fixed solutions are