I am lost.

Find the spectrum for a 0.1 second sample of a 50 Hz sinusoidal voltage wave.

All I can get out of this question so far that:

V=Asin(314t)

Do I use

\(S(f)=A\int^{.1}_{0}\sin{314t}e^{-j314t} dt\)

 

Do I use

\(S(f)=A\int^{.1}_{0}\sin{314t}e^{-j314t} dt\)

No - you use

\(S(\omega)=A\int^{.1}_{0}sin(314t)e^{-j\omega t} dt\)

Perform the integration to determine the general relationship for S(ω) then plot S(ω) for an indicative range of values of the variable ω.