Answer: Both line directions.
- A Both line directions
- B One line direction only
- C The line of intersection
- D All vectors in space
Correct answer: A. Both line directions
Explanation: For two coplanar lines with direction vectors b and d, the plane they lie in has normal b x d. The normal is perpendicular to both b and d.
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