2(i)) Consider a point P in space, having coordinates (x, y, z) with
respect to the origin O(0, 0, 0) Then, the vector OP
uuur  having O and P as its initial and
terminal points, respectively, is called the position vector of the point P with respect
to O Using distance formula (from Class XI), the magnitude of OP
uuur  (or rr ) is given by
| OP |
uuur  =
2
2
2
x
y
z
+
+
In practice, the position vectors of points A, B, C, etc