Zaymiey

📐 Mathematics  ·  Three Dimensional Geometry  ·  JEE

The shortest distance between two parallel lines r = a + lambda*b and r = c + mu*b is:

Answer: |(a-c) x b| / |b|.

  • A |(a-c) . b| / |b|
  • B |(a-c) x b| / |b|
  • C |a - c|
  • D |(a-c) + b| / |b|

Correct answer: B. |(a-c) x b| / |b|

Explanation: For parallel lines (same direction b), shortest distance = |(a-c) x b| / |b|, the perpendicular distance between them.

zxyOP (x, y, z)

Three mutually perpendicular axes x, y, z meeting at the origin O, with a point P located by its (x, y, z) coordinates.

Concept context

Lines and planes in 3D space, direction cosines, distances, and angles

Read the full Three Dimensional Geometry notes →