Question

What is the frequency of `f(theta)= sin 7 t - cos 9 t`?

Answer 1

`(4pi)^2/63`

Explanation:

Frequency of sin 7t --> `2pi/7` or 360/7 deg
Frequency of cos 9t --> `(2pi)/9` or 360/9 deg
Frequency of (ft) --> `((2pi)/7)((2pi)/9) = (4pi)^2/63`
or `(360/7)((360)/9)= ((129,600)/63)` deg