And As the spectrum of a discrete time sign, this identical spectrum will periodically repeat if we prolonged the frequency better outside of $f_s$ these kinds of which the spectrum demonstrated is additionally the identical spectrum in each and every frequency band from $nf_s$ to $(n+one)f_s$ for any integer $n$. https://pginsector15gurugram.mystrikingly.com/blog/book-modern-pg-for-boys-in-gurgaon-osmstays/i/view_as_owner