Question

What is the period of `f(t)=sin( (t)/4 )+ cos( (t)/5 )`?

Answer 1

`40pi`

Explanation:

The period for sin kt and also cos kt is `2pi/k`.

Separately, the periods of `sin(t/4) and cos(t/5)` are `8pi and 10pi`, respectively.

So, for the sum it is the least common multiple `40pi`.