This question makes me confused: If $h \in R^n $ let $\tau_h $ be the translation operator. Determine all distributions $u$ such that $\tau_h u=u$
I started by taking Fourier transform for both sides, but then I don`t know!
$ u(x-a)=u(x)$
$ e^{-i2\pi x a} u^{\land}=u^{\land}$
then??