A sinusoidal carrier wave has a constant amplitude and a frequency of 
. The carrier wave is modulated by a signal wave such that a 
displacement of the signal wave causes a change in frequency of 
. The signal wave has frequency 
and amplitude 
.
State the name of this type of modulation of the carrier wave.
For this modulated carrier wave, determine the variation, if any, in:
its amplitude
its frequency.
at a rate of 8000 times per second.
