>>367

 y(x) = u(x)e^(-xxx/3)
を与式に入れると
 du/dx = e^(xxx/3),
 u(x) = u(0) + ∫[0,x] e^(ttt/3) dt,
 y(x) = e^(-xxx/3) {y(0) + ∫[0,x] e^(ttt/3) dt },
かな