两边对x求导得dy/dx+1=e^(xy)*(y+x*dy/dx整理得：[1-x*e^(xy)]*dy/dx=[y*e^(xy)-1]所以：dy/dx=[y*e^(xy)-1]/[1-x*e^(xy)]
两边对x求导得y'+1=e^(xy)*(y+xy')dy/dx=y'=[e^(xy)*y-1]/[1-e^(xy)*x]
