Q42 / 160 · TS EAMCET 2022 (20 Jul Shift 1) · Mathematics
The range of the real valued function $f(x)=|x-2|+|x-3|$ is
- A$[3, \infty)$
- Correct answerB$[1, \infty)$
- C$[2, \infty)$
- D$(0,2] \cup[3, \infty)$
Solution
Given function $\mathrm{f}(\mathrm{x})=|\mathrm{x}-2|+|\mathrm{x}-3|$
We will thick on three point $\mathrm{x} \leq 2,2 < \mathrm{x} < 3$ and $\mathrm{x} \geq 3$
For $\mathrm{x} \leq 2$
$$
f(x)=-x+2-x+3=-2 x+5
$$
For $2 < \mathrm{x} < 3$
$$
f(x)=x-2-x+3=1
$$
For, $x \geq 3$,
$$
\begin{aligned}
& f(x)=x-2+x-3 \\
& =2 x-5 \\
& \begin{cases}-2 x+5, & x \leq 2 \\
1, & 2 < x < 3 \\
2 x-5, & x \geq 3\end{cases}
\end{aligned}
$$
Now, take $\mathrm{x}=1,2$ for $\mathrm{x} \leq 2$ then $\mathrm{f}(\mathrm{x})=3$ and $\mathrm{f}(\mathrm{x})=1$ respectively.
So, It will give always greater than or equal to 1 .
Similarly, for $\mathrm{x} \geq 3$ function always gives values greater than or equal to 1 .
So, Range is $[1, \infty)$
Therfore, option (b) is correct.
Hence, the correct answer is option: 'B'.