x2+1)(y2-1)dx+xydy=0 ydy/(y^2-1)=-(x+1/x)dx 两边积分 (1/2)ln|y^2-1|=-x^2/2-ln|x|+C1 ln|y^2-1|=-x^2-2ln|x|+2C1 ln|y^2-1|=ln[e^2C1/e^(x^2)*x^2] y^2-1=正负[e^2C1/e^(x^2)*x^2] 设正负e^2C1=C y^2-1=C/e^(x^2...