Describe what is meant by frequency modulation (FM).
A sinusoidal carrier wave has a frequency of 
and an amplitude of 
. The carrier wave is frequency modulated by a sinusoidal wave of frequency 
and amplitude 
. The frequency deviation of the carrier wave is 
. Determine, for the modulated carrier wave,
the amplitude,
the maximum frequency,
the minimum frequency,
the number of times per second that the frequency changes from maximum to minimum and then back to maximum.
.
