Find the domain of $\sin^{-1}(x^2 - 4)$. |
$[-\sqrt{5}, \sqrt{5}]$ $[-\sqrt{5}, -\sqrt{3}] \cup [\sqrt{3}, \sqrt{5}]$ $[\sqrt{3}, \sqrt{5}]$ $(-\infty, -\sqrt{3}] \cup [\sqrt{3}, \infty)$ |
$[-\sqrt{5}, -\sqrt{3}] \cup [\sqrt{3}, \sqrt{5}]$ |
The correct answer is Option (2) → $[-\sqrt{5}, -\sqrt{3}] \cup [\sqrt{3}, \sqrt{5}]$ ## $-1 \le (x^2 - 4) \le 1$ $\Rightarrow 3 \le x^2 \le 5$ $\Rightarrow \sqrt{3} \le |x| \le \sqrt{5}$ $\Rightarrow x \in [-\sqrt{5}, -\sqrt{3}] \cup [\sqrt{3}, \sqrt{5}]$ So, required domain is $[-\sqrt{5}, -\sqrt{3}] \cup [\sqrt{3}, \sqrt{5}]$ |