So I have an AM signal, given by: $$v(t)=50\cos(\pi 10^{6} t )+ 20\sin(\pi 10^3t)\cos(\pi 10^6 t)$$ I was asked to sketch the spectrum of the signal obtained, so I found the fourier transform of it, and that's what I got,
$$V(f)=25 \left[ \delta(f - 500k)+ \delta(f+500k)\right]-5i\left[\delta(f-999.5k)-\delta(f+999.5k) \right]-5i\left[\delta(f-500.5k)-\delta(f+500.5k) \right]$$
And so far I only knew how to sketch the first term, as shown below,
But I don't know how to sketch the terms with the $-5i$.