The Continuous-Discrete Sampling Demo shows the continuous and discrete spectra and signals during sampling.
Do This:

1. Adjust the input frequency \(f_0\). What happens when it reaches half the sampling rate, \(f_s\)?
2. Continue to increase the input frequency \(f_0\). What happens to the output frequency when the input increates from \(f_s/2\) to \(f_s\)?
3. What happens to the output frequency when the input increases from \(f_s\) to \(3/2 f_s\)?
4. Based on what you have seen, what do you think will happen with the input increases from \(3/2 f_s\) to \(2f_ss\)?