Q78 / 200 · Manipal (MET) 2011 · Mathematics
The domain and range of $f(x)=\sin ^{-1}[x]$ are
- A$[0,2),\left\{-\frac{\pi}{2}, \frac{\pi}{2}\right\}$
- Correct answerB$[-1,2),\left\{-\frac{\pi}{2}, 0, \frac{\pi}{2}\right\}$
- C$[-1,2),\left\{-\pi, \frac{-\pi}{2}, 0, \frac{\pi}{2}, \pi\right\}$
- DNone of the above
Solution
$f(x)=\sin ^{-1}[x]$ is defined, if $-1 \leq[x] \leq 1$
$\Rightarrow \quad[x]=\{-1,0,1\}$
$\therefore \quad x \in[-1,2)$
$\therefore$ Range is $\left\{\sin ^{-1}(-1), \sin ^{-1} 0, \sin ^{-1} 1\right\}$
$=\left\{-\frac{\pi}{2}, 0, \frac{\pi}{2}\right\}$
Hence, the correct answer is option: 'B'.