In HW1 I used the signal cos(t-2) so I will use that as my example signal.
A1. If sampled at an integer value it is aperiodic, but if sampled at any multiple of $ \pi $ it will be periodic.
A2. The signal $ f(t)={ 2 \over(t-3)} $ is aperiodic. If we take the signal only from [2 to 4] shift and add the signal together multiple times we can get a periodic signal with period 2.