And because the spectrum of a discrete time signal, this similar spectrum will periodically repeat if we extended the frequency bigger beyond $f_s$ this sort of that the spectrum revealed is likewise precisely the same spectrum in every single frequency band from $nf_s$ to $(n+one)f_s$ for virtually any integer $n$. https://share.evernote.com/note/ebea7c23-af75-8024-d7e5-a193c523ffba