cos(xy)=(xy)^2求dy

问题描述:

cos(xy)=(xy)^2求dy
请高人解析一下

两面对x同时求导得
-sin(xy)(y+xy')=2xy(y+xy')
整理得 -ysin(xy)-2xy²=[xsin(xy)+2x²y]y'
y'=-[ysin(xy)+2xy²]/[xsin(xy)+2x²y]