Question

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

Answer 1

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)`