If $cos^{-1}\left(\frac{n}{2\pi}\right) > \frac{2\pi}{3}$, then maximum and minimum values of integer n are respectively
Answer & explanation
Correct answer: option 2
We have,
$cos^{-1}\left(\frac{n}{2\pi}\right) > \frac{2\pi}{3}$
$ ⇒ - 1 < \frac{n}{2\pi} < -\frac{1}{2}$
$ ⇒ -2 \pi < n < - \pi $
$ ⇒ -6.18 < n < - 3.14 $
$ ⇒ -6 ≤ n ≤ -4 $ where n ∈ Z.