It is also a sufficient condition for secondorder linear differentialequation with varied coefficient to be integrable.
对于二阶变系数线性微分方程来说，这也是可积的一个充分条件。
2
An important case is the linear homogeneous second-orderdifferentialequation with constant coefficients.
一种重要的情形是常系数二阶线性齐次微分方程。
3
The driveline for a tractor vehicle is simplified as a 2-DOFs(degree of freedom)torsional vibration system, and is described as a second-orderdifferentialequation.