e^(x+y)+xy=0
对两边求导得:
y'e^(x+y)+y+xy'=0
当x=1,y=-1时,
y'e^0-1+y'=0
2y'=1
y'=1/2
所以切线为y+1=1/2(x-1),即y=x/2-3/2
法线为y+1=-2(x-1).即y=-2x+1求导不对啊e^(x+y)+xy=0对两边求导得:(1+y')e^(x+y)+y+xy'=0当x=1,y=-1时,(1+y')e^0-1+y'=02y'=0y'=0所以切线为y=-1法线为x=1(￣∇￣)谢谢