Determine in each case whether the indicated signal x(t) isperiodic. If x(t) is periodic, find its fundamental frequence in Hzand fundamental period in seconds.
a)x(t) = 3-5cos(1080t) + 7cos(2160πt)
b)x(t) = 5sin(1080πt) - 7cos(3240πt)
c)x(t) = cos(500πt) + sin(700πt)