e^xy+xy+y=3
那么对x求导得到
e^xy *(xy)' +(xy)' +y'=0
而
(xy)'=y+x *y'
所以
e^xy *(y+x *y') +(y+x *y') +y'=0
于是
(x*e^xy+x+1)y' = -y*e^xy-y
得到
y'=(-y*e^xy-y) / (x*e^xy+x+1)
e^xy+xy+y=3
那么对x求导得到
e^xy *(xy)' +(xy)' +y'=0
而
(xy)'=y+x *y'
所以
e^xy *(y+x *y') +(y+x *y') +y'=0
于是
(x*e^xy+x+1)y' = -y*e^xy-y
得到
y'=(-y*e^xy-y) / (x*e^xy+x+1)