Three Dimensional Geometry Question 45

Question: The shortest distance between the lines $ \frac{x-3}{3}=\frac{y-8}{-1}=\frac{z-3}{1} $ and $ \frac{x+3}{-3}=\frac{y+7}{2}=\frac{z-6}{4} $ is

[RPET 2001; MP PET 2002]

Options:

A) $ \sqrt{30} $

B) $ 2\sqrt{30} $

C) $ 5\sqrt{30} $

D) $ 3\sqrt{30} $

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Answer:

Correct Answer: D

Solution:

S.D. $ = $ $ \frac{ \begin{vmatrix} 6 & 15 & -3 \\ 3 & -1 & 1 \\ -3 & 2 & 4 \\ \end{vmatrix} }{\sqrt{{{(-4-2)}^{2}}+{{(12+3)}^{2}}+{{(6-3)}^{2}}}} $ $ =\frac{270}{\sqrt{270}}=\sqrt{270} $ = $ 3\sqrt{30} $ .