Question

What is the frequency of `f(theta)= sin 6 t - cos 9 t`?

Answer 1

`(2pi)/3`

Explanation:

Frequency of sin 6t --> `(2pi)/6 = pi/3`
Frequency of cos 9t --> `(2pi)/9`
Find least common multiple of `pi/3 and (2pi)/9`

pi/3 ... x (2) ... --> (2pi)/3
(2pi)/9 ... (3) ... --> (2pi)/3

Frequency of f(t) --> (2pi)/3