I encountered the following question on a test, and I'm not sure of the theory behind it. Could someone please explain?
When a signal with spectrum ranging from 13 MHz to 15 MHz is mixed with (i.e., multiplied by) a 14-MHz sine wave, which of the following frequency ranges does NOT contain frequencies of the resulting mixed signal?
- (A) From 0 to 1 MHz
- (B) From 13 to 14 MHz
- (C) From 27 to 28 MHz
- (D) From 28 to 29 MHz
- (E) All of the above ranges contain frequencies of the resulting signal