ydx+(x-y^3)dy=0 ydx+xdy-y^3dy=0 d(xy-y^4/4)=0 积分得到 xy-y^4/4=C

问题描述:

ydx+(x-y^3)dy=0
ydx+xdy-y^3dy=0
d(xy-y^4/4)=0
积分得到 xy-y^4/4=C