Question

What is the period of `f(theta) = tan ( theta) - cos ( (7theta)/9)`?

Answer 1

`18pi`

Explanation:

Period of tan t --> `pi`
Period of `cos ((7t)/9)` --> `9(2pi)/7 = 18pi/7`
Find least common multiple of `pi and (18pi)/7`

`pi` ...x (18) --> `18pi`
`(18pi)/7` ...x (7) --> `18pi`
Period of f(t) --> `18pi`