Evaluate each of the following: `sec^(-1)(sec(7pi)/3)` (ii) `sec^(-1)(sec(9pi)/5)` (iii) `sec^(-1){sec(-(7pi)/3)}`

Explanation

(i)
We know that
$$ \sec ^{-1}(\sec \theta)=\theta, \quad[0, \pi / 2) \cup(\pi / 2, \pi] $$
We have
$$
\begin{aligned}
...