What is the frequency of #f(theta)= sin 18 t - cos 66 t #?

1 Answer
Jul 18, 2017

The frequency is #=3/pi#

Explanation:

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

The period of #sin18t# is #T_1=2/18pi=1/9pi=11/99pi#

The period of #cos66t# is #T_2=2/66pi=1/33pi=3/99pi#

The LCM of #T_1# and #T_2# is #T=33/99pi=1/3pi#

The frequency is

#f=1/T=3/pi#