Question

Domain of ${\cos }^{-1}[x]$ is

• A. [-1,2]
• B. [-1,2)
• C. (-1,2]
• D. None of these

Answer 1

Answer: (B)

$0\le {\cos }^{-1}[x]\le \pi ,-1\le [x]\le 1$
$\Rightarrow -1\le x<2$
$\Rightarrow x\in [-1,2)$