PERIODIC FUNCTION
$ e^{2i*\Pi*} $ is a periodic function since it has the form $ e^{N*W_o*\Pi} $, where $ W_o = 1 and N = 2 $
By definition, $ e^{N*W_o*\Pi} $ is a periodic function if $ \frac{W_o}{2*\Pi} $ is a rational number.
$ \frac{W_o}{2*\Pi} $ using the above numbers, yields a result of $ \frac{1}{2} $ which is a rational number.
NON-PERIODIC FUNCTION
$ e^{200i} $ is not a periodic function since $ \frac{W_o}{2*\Pi} $ yields $ \frac{100}{\Pi} $ which is not a rational number.
