simple question, but I cant seem to understand how they got the answer. I have $x(t)$ as a signal, and I'm told that its Nyquist frequency is $\omega_0$
I'm asked - what is the Nyquist frequency of this next signal: $$ x(t)\cos^2(\omega_0t)$$
after playing with it I got the Fourier transform of it $$0.5(j\omega)+0.25X(j(\omega+2\omega_0))+0.25X((j(\omega-2\omega_0))$$
So I got the same signal (different amplitude) and two more of it shifted in frequency. I draw it and concluded that the Nyquist frequency is $3\omega_0$ Buy I'm wrong and don't know how to get to the correct answer. The formal answer is $$2(\omega_0/2 +2\omega_0)=5\omega_0$$ Thanks.