x^2y"+xy'-y=0 x^2y"=y-xy' -------2边同除以x^2 y"= (y-xy')/x^2 (y')'= - (y/x)' y'= - y/x +C -------2边同乘以 x xy'+y=Cx (xy)'= (Cx^2)' xy= C1x^2+C2 y= C1 x + C2/x ------------通解 当C1=1,C2=0时,特解为 y=x
