Question

In three dimensions, the coordinate axes of a rectangular cartesian coordinate system are

• A. three mutually parallel lines
• B. three mutually perpendicular lines
• C. two mutually perpendicular lines and any two parallel
• D. None of these

Answer 1

The correct option is B three mutually perpendicular lines

In three dimensions, the coordinate axes, i.e. x, y and z axes of a rectangular cartesian coordinate system are three mutually perpendicular lines.

The word rectangular is used to indicate perpendicularity among the axes.