A radio receiver is designed using a band-pass filter with frequency centered on 455kHz. It can be tuned to different stations by multiplying the incoming signal by a sine wave of correctly chosen frequency. The incoming signal is a 600kHz sine wave. What must be the frequency of the multiplying sine wave to make the signal pass through the filter?
All I have is a trigonometric identity. I'm confused. How do I even multiply sine waves?
All I have is a trigonometric identity. I'm confused. How do I even multiply sine waves?