I have this function
$$ sin(5t - \frac{\pi}{4})U(t+8) $$
I know the Fourier Transform of $sin(5t - \frac{\pi}{4})$, which is
$$ \frac{e^{-\frac{\pi^2}{2}fj}}{2j}\left [\delta (f-\frac{5}{2 \pi}) -\delta(f +\frac{5}{2 \pi}) \right ] $$
So, how would be the Fourier Transform with the shifted unit step?