1.x(t) is real and odd.
2.x(t) is periodic with period T = 8
3. -9 <= signal <=9
4. $ a_0 = 9 $
it should have a sin wave.
since T = 8,
$ w_0 = \frac {2\pi}{8} $
so,
$ x(t) = 9sin(\frac{\pi}{4}t) $
