Q93 / 160 · AP EAMCET 2003 · Mathematics
If $f: R \rightarrow R$ and $g: R \rightarrow R$ are given by $f(x)=|x|$ and $g(x)=[x]$ for each $x \in R$, then $\{x \in R: g(f(x)) \leq f(g(x))\}$ is equal to
- A$Z \cup(-\infty, 0)$
- B$(-\infty, 0)$
- C$Z$
- Correct answerD$R$
Solution
We have,
$f(x)=|x| \text { and } g(x)=[x]$
Now, $\quad g(f(x)) \leq f(g(x))$
$\Rightarrow \quad g(|x|) \leq f([x])$
$\therefore \quad[|x|] \leq|[x]| \forall x \in R$
Hence, the correct answer is option: 'D'.