Q85 / 150 · MHT CET 2023 (13 May Shift 1) · Mathematics
The equation of the line passing through the point $(-1,3,-2)$ and perpendicular to each of the lines $\frac{x}{1}=\frac{y}{2}=\frac{z}{3}$ and $\frac{x+2}{-3}=\frac{y-1}{2}=\frac{z+1}{5}$ is
- A$\frac{x+1}{2}=\frac{y-3}{7}=\frac{z+2}{4}$
- Correct answerB$\frac{x+1}{2}=\frac{y-3}{-7}=\frac{z+2}{4}$
- C$\frac{x-1}{2}=\frac{y+3}{-7}=\frac{z+2}{4}$
- D$\frac{x-1}{2}=\frac{y+3}{7}=\frac{z-2}{4}$
Solution
Let $\mathrm{a}, \mathrm{b}, \mathrm{c}$ be the direction ratios of the required line. Since the line is perpendicular to the lines with d.r.s. $1,2,3$ and $-3,2,5$.
$$
\begin{aligned}
\therefore \quad & a+2 b+3 c=0 \\
& \text { and }-3 a+2 b+5 c=0 . \\
& \Rightarrow \frac{a}{2}=\frac{b}{-7}=\frac{c}{4}
\end{aligned}
$$
....[From (i) and (ii)]
$\therefore \quad$ Equation of the required line is
$$
\frac{x+1}{2}=\frac{y-3}{-7}=\frac{z+2}{4}
$$
Hence, the correct answer is option: 'B'.