Q45 / 105 · JEE Main 2008 · Mathematics
The perpendicular bisector of the line segment joining $P(1,4)$ and $Q(k, 3)$ has $y$-intercept - 4. Then a possible value of $k$ is
- A1
- B2
- C$-2$
- Correct answerD$-4$
Solution
Slope of bisector $=k-1$
Middle point $=\left(\frac{\mathrm{k}+1}{2}, \frac{7}{2}\right)$
Equation of bisector is
$y-\frac{7}{2}=(k-1)\left(x-\frac{(k+1)}{2}\right)$
Put $\mathrm{x}=0$ and $\mathrm{y}=-4$
$$
\Rightarrow k=\pm 4
$$
Hence, the correct answer is option: 'D'.