Question

What is the frequency of `f(theta)= sin 4 t - cos 24 t`?

Answer 1

`2/pi`

Explanation:

`f( t ) = sin 4t - cos 24t`

The separate frequencies for the two terms are

`F_1 =` reciprocal of the period `= 4/( 2pi) = 2/pi` and

#F_2 = 24/(2pi) = 12/pi.

The frequency F of `f ( t )` is given by

#1/F = L/F_1 = M/F_2, for befitting integers L and M, givnig

Period `P = 1/F = Lpi/2 = Mpi/12`.

Note that 2 is a factor of 12.

Easily, the lowest choice is L = 1, M = 6 and

`P = 1/F = pi/2` giving `F = 2/pi`.