If a, b, c are unit vectors such that a + b + c = 0, then the value of a · b + b · c + c · a is equal to
3/2
1
3
- 3/2
The perpendicular distance of the point P(6, 7, 8) from XY-plane is
6
7
5
8
D.
8
Accordmg to the question
Distance of any point from XY - plane is =
=