解微分方程 yy''-(y')^2=y^2lny

问题描述:

解微分方程 yy''-(y')^2=y^2lny

[yy''-(y')^2] / (y^2) = lny
(y'/y) ' = lny
y'/y=y(lny-1)
y'=y^2(lny-1)
.