二阶、三阶变系数线性微分方程可降阶的一个类型

A Type Which Order Can be Depressed for Second or Third Order Linear Differential Equation with Varied Coefficient

本文给出二阶、三阶变系数线性微分方程可降阶的一个充分条件。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。

This paper gives a condition under which order can be depressed for second or third order linear differential equation with varied coefficient.It is also a sufficient condition for second order linear differential equation with varied coefficient to be integrable.