# What is the period of #f(t)=sin( t / 18 )+ cos( (t)/21 ) #?

##### 2 Answers

#### Explanation:

The periods dor both sin kt and cos kt is

Here, the periods of the separate oscillations given by

For the compounded oscillation f(t), the period is given by

the period

integers L and M. So,

See how it works.

Note that when this P is halved, the first term would change its sign..

#### Explanation:

Period of

Period of

Least common multiple of

Period of f(t) -->