-- Proving the Sampling Theorem --
The sampling can be represented by "Impulse-train Sampling."
$ x_p(t) = ? $ $ x_p(t) = x(t)p(t) $ $ x_p(t) = x(t)\sum_{n=-\infty}^{\infty} \delta(t-nT) $
We can recover $ x(t) $ from $ x_p(t) $ as follows:
$ x_p(t) $\rightarrow$ H(omega) $\rightarrow$ x_r(t) $
Where $ H(omega) $ is a filter with gain equal to the period of the signal and a cutoff frequency of $ omega_c $.
$ omega_c $ satisfies $ omega_m < omega_c < omega_s - omega_m<\math>. $
