# Questions & Answers of Frequency response

The impulse response of a system is $h\left(t\right)=tu\left(t\right)$.For an input $u\left(t-1\right)$ , the output is

For a periodic signal $v\left(t\right)=30\mathrm{sin}100t+10\mathrm{cos}300t+6\mathrm{sin}\left(500t+\mathrm{\pi }/4\right)$, the fundamental frequency in rad/s is