∫e^(y/x) dy
= 1/x *∫e^(y/x) d(y/x)
=1/x * e^(y/x) +C(C为常数)答案是x*e^(y/x)不好意思随手写错了……∫e^(y/x) dy=x *∫e^(y/x) d(y/x)=x * e^(y/x) +C(C为常数)