Q41 / 160 · TS EAMCET 2022 (20 Jul Shift 2) · Mathematics
If $[x]$ represents the greatest integer function, then the set of all real values of $x$ for which $f(x)=\sqrt{\frac{[x]-x}{x-[x]}}$ is real is
- Correct answerA$\phi$
- B$\mathbb{R}$
- C$\mathbb{Z}$
- D$\mathbb{R}-\mathbb{Z}$
Solution
$f(x)=\sqrt{\frac{[x]-x}{x-[x]}}=\sqrt{\frac{-\{x-[x]\}}{x-[x]}}=\sqrt{-1}=i$
$$
\Rightarrow \mathrm{f}(\mathrm{x})=\mathrm{i} \forall \mathrm{x} \leftarrow \mathbb{R}
$$
$\Rightarrow \nexists$ any $\mathrm{x} \leftarrow \mathrm{R}$ s.t $\mathrm{f}(\mathrm{x}) \leftarrow \mathbb{R}$.
Hence, the correct answer is option: 'A'.