2x(ye^x^2+2x^2)dx=e^x^2dy
ye^x^2dx^2-e^x^2dy=-4x^3dx
yde^x^2/e^x^4-dy/e^x^2=de^(-x^4)
d(y/e^x^2)=de^(-x^4)
y/e^x^2=e^(-x^4)+C
通解y=e^(-x^2)+Ce^x^2