Verified Solution • 2025–26 Session moderate

QJEEM22Maa427: JEE Main 2022 Mathematics - Class 12 JEEM22Maa427 Solution: The shortest distance between the lines and is :

The shortest distance between the lines x+7−6=y−67=z\frac{x+7}{-6}=\frac{y-6}{7}=z and 7−x2=y−2=z−6\frac{7-x}{2}=y-2=z-6 is :

Multiple Choice Options

  • A 2292 \sqrt{29}
  • B 1
  • C 3729\sqrt{\frac{37}{29}}
  • D 292\frac{\sqrt{29}}{2}

Step-by-Step Verified Solution

L1:x+76=y−67=z−01{L_1}:{{x + 7} \over 6} = {{y - 6} \over 7} = {{z - 0} \over 1}

Any point on it a→1(−7,6,0){\overrightarrow a _1}( - 7,6,0) and L1 is parallel to b→1(−6,7,1){\overrightarrow b _1}( - 6,7,1)

L2:x−7−2=y−21=z−61{L_2}:{{x - 7} \over { - 2}} = {{y - 2} \over 1} = {{z - 6} \over 1}

Any point on it a→2(7,2,6){\overrightarrow a _2}(7,2,6) and L2 is parallel to b→2(−2,1,1){\overrightarrow b _2}( - 2,1,1)

Shortest distance between L1 and L2

=∣(a→2−a→1) . (b→1×b→2)∣b→1×b→2∣∣=∣(−14,4,−6) . (3,2,4)9+4+16∣= \left| {{{({{\overrightarrow a }_2} - {{\overrightarrow a }_1})\,.\,({{\overrightarrow b }_1} \times {{\overrightarrow b }_2})} \over {\left| {{{\overrightarrow b }_1} \times {{\overrightarrow b }_2}} \right|}}} \right| = \left| {{{( - 14,4, - 6)\,.\,(3,2,4)} \over {\sqrt {9 + 4 + 16} }}} \right|

=229= 2\sqrt {29} .

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