$4)[30$ points$]$ If a time domain signal; g$($t$)$ has a spectrum G$($l$)$ given as below

G$($t$)$ A

$-10$

$2$

$10$ f$.$ Hz

$($a$)$ Draw the energy spectral density $($ESD$)$ of this signal.

$($b$)$ Find the total energy of g$($t$)=($c$)$ v$($t$)=$ g$($t$)$ cos $(10$mt$)$ESD of nu$($t$)$

$($d$)$ Find energy of v$($t$)$