$3\mathrm{.}7-2)$ a periodic signal x$($t$)=1+2$cost$(5*$ pi $*$ t$)+3$sin$(14*$ pi $*$ t$)$ is applied to an LTIC system to produce output y$($t$).$ a$)$ determine w$0$ the fundamental radian frequency of x$($t$).$ b$)$ determine Dn$,$ the exponential fourier series spectrum of x$($t$)$