∵xy"+y'=0 ==>xdy'/dx+y'=0==>dy'/y'=-dx/x==>ln│y'│=-ln│x│+ln│C1│ (C1是积分常数)==>y'=C1/x∴y=∫C1/xdx=C1ln│x│+C2 (C2是积分常数)故原微分方程的通解是y=C1ln│x│+C2 (C1,C2是积分常数).
