Verified Solution • 2025–26 Session moderate

QJEEM24Maddab: JEE Main 2024 Mathematics - Class 12 JEEM24Maddab Solution: The shortest distance between the lines and is:

The shortest distance between the lines x−34=y+7−11=z−15\frac{x-3}{4}=\frac{y+7}{-11}=\frac{z-1}{5} and x−53=y−9−6=z+21\frac{x-5}{3}=\frac{y-9}{-6}=\frac{z+2}{1} is:

Multiple Choice Options

  • A 185563\frac{185}{\sqrt{563}}
  • B 187563\frac{187}{\sqrt{563}}
  • C 178563\frac{178}{\sqrt{563}}
  • D 179563\frac{179}{\sqrt{563}}

Step-by-Step Verified Solution

Given lines are

x−34=y−(−7)−11=z−15\frac{x-3}{4}=\frac{y-(-7)}{-11}=\frac{z-1}{5} and

x−53=y−9−6=z−(−2)1\frac{x-5}{3}=\frac{y-9}{-6}=\frac{z-(-2)}{1}

Shortest distance between two lines,

amp;d=∣(a⃗2−a⃗1)⋅(b⃗1×b⃗2)∣∣(b⃗1×b⃗2)∣amp;a⃗2−a⃗1=2i^+16j^−3k^ and amp;b⃗1×b⃗2=∣i^amp;j^amp;k^4amp;−11amp;53amp;−6amp;1∣=19i^+11j^+9k^amp;∴d=187563\begin{aligned}& d=\frac{\left|\left(\vec{a}_2-\vec{a}_1\right) \cdot\left(\vec{b}_1 \times \vec{b}_2\right)\right|}{\left|\left(\vec{b}_1 \times \vec{b}_2\right)\right|} \\& \vec{a}_2-\vec{a}_1=2 \hat{i}+16 \hat{j}-3 \hat{k} \text { and } \\& \vec{b}_1 \times \vec{b}_2=\left|\begin{array}{ccc}\hat{i} & \hat{j} & \hat{k} \\4 & -11 & 5 \\3 & -6 & 1\end{array}\right|=19 \hat{i}+11 \hat{j}+9 \hat{k} \\& \therefore \quad d=\frac{187}{\sqrt{563}}\end{aligned}

Related Learning Resources & Exam Preparation