What is the frequency of #f(theta)= sin 2 t - cos 8 t #?

1 Answer
Nov 30, 2017

The frequency is #=(1/pi) Hz#

Explanation:

The period of the sum of #2# periodic functions is the LCM of their periods

The function is #f(theta)=sin(2t)-cos(8t)#

The period of #sin(2t)# is #T_1=(2pi)/2=(8pi)/(8)#

The period of #cos(8t)# is #T_2=(2pi)/8=(2pi)/(8)#

The LCM of #(8pi)/8# and #(2pi/8)# is #T=(8pi/8)=pi#

The frequency is #f=1/T=1/pi Hz#

graph{sin(2x)-cos(8x) [-1.125, 6.67, -1.886, 2.01]}