For a message signal m_(t) = cos(2πf_mt) and carrier frequency f_c, which one of the following represents a SSB signal?

For \(\rm SSB\), the general expression is

\(\rm {X_{SSB}}\left( t \right) = m\left( t \right)\cos {\omega _c}t \pm \hat m\left( t \right)\sin {\omega _c}t\)

for\(\rm \;m\left( t \right) = \cos \left( {2\pi {f_m}t} \right)\),

We get,

\(\rm {X_{SSB}}\left( t \right) = \cos \left( {2\pi {f_m}t} \right)cos{\omega _c}t \pm \sin \left( {2\pi {f_m}t} \right)\sin {\omega _c}t \\ \ \ \ \ \ \ \ \ \ \ \ \ \ = {\rm{cos}}\left[ {2\pi \left( {{f_c} + {f_m}} \right)t} \right]\)