What is the frequency of #f(theta)= sin 4 t - cos 13 t #?

1 Answer
Jan 6, 2017

The frequency is #=1/(2pi)#

Explanation:

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

The period of #sin4t# is #=(2pi)/4=pi/2=(13pi)/26#

The period of #cos13t# is #=(2pi)/13=(4pi)/26#

The LCM of #(13pi)/26# and #(4pi)/26# is #=(52pi)/26=2pi#

The period is #T=2pi#

The frequency is #f=1/T=1/(2pi)#