Answer: Midpoint of AB.
- A A itself
- B B itself
- C Midpoint of AB
- D (3,2,6)
Correct answer: C. Midpoint of AB
Explanation: Midpoint M = (3,2,6). Check: 3+2+6=11 not 6. Parametric: (2+2t,1+2t,3+6t). Sum = 6+10t = 6, t=0. Point = A = (2,1,3). So answer is A itself.
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