dy/dx=-x(y^2-1)/y(x^2-1)ydy/(y^2-1)=-xdx/(x^2-1)dy^2/(y^2-1)=-dx^2/(x^2-1)d(y^2-1)/(y^2-1)=-d(x^2-1)/(x^2-1)ln(y^2-1)=-ln(x^2-1)-lnCln(y^2-1)+ln(x^2-1)+lnC=0ln[C(x^2-1)(y^2-1)]=0C(x^2-1)(y^2-1)=1