Mathematics · 3D Geometry

JEE Main 2024 — 1 February, Shift 1 — Question 20

If the shortest distance between the lines x−λ−2=y−21=z−11\frac{x-\lambda}{-2}=\frac{y-2}{1}=\frac{z-1}{1} and

x−31=y−1−2=z−21\frac{x-\sqrt{3}}{1}=\frac{y-1}{-2}=\frac{z-2}{1} is 1 , then the sum of all possible values of λ\lambda is :

  1. Option A:

    00

  2. Option B:

    232 \sqrt{3}

    Correct
  3. Option C:

    333 \sqrt{3}

  4. Option D:

    −23-2 \sqrt{3}

Answer: B

Step-by-step solution

Passing points of lines L1& L2\mathrm{L}_{1} \& \mathrm{~L}_{2} are

(λ,2,1)&(3,1,2)(\lambda, 2,1) \&(\sqrt{3}, 1,2)

S.D =∣3−λ−11−2111−21∣∣i^j^k^−2111−21∣=\frac{\left|\begin{array}{ccc}\sqrt{3}-\lambda & -1 & 1 \\-2 & 1 & 1 \\1 & -2 & 1\end{array}\right|}{\left|\begin{array}{ccc}\hat{i} & \hat{j} & \hat{k}\\ -2 & 1 & 1\\ 1 & -2 & 1\end{array}\right|}

1=∣3−λ3∣1=\left|\frac{\sqrt{3}-\lambda}{\sqrt{3}}\right|

λ=0,λ=23\lambda=0, \lambda=2 \sqrt{3}

Answer key and solution verified before publishing.

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Exam
JEE Main 2024
Subject
Mathematics
Chapter
3D Geometry
Topic
Skew lines & shortest distance between them