Zaymiey

📐 Mathematics  ·  Three Dimensional Geometry  ·  JEE

Three points A, B, C are collinear if the vectors AB and AC satisfy:

Answer: AB x AC = 0 (zero vector).

  • A AB . AC = 0, the dot product condition
  • B AB + AC = 0, a vector sum condition
  • C AB x AC = 0 (zero vector)
  • D AB = BC, equal vector magnitudes

Correct answer: C. AB x AC = 0 (zero vector)

Explanation: A, B, C are collinear if vector AB and vector AC are parallel, i.e., AB x AC = zero vector.

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 →