28
Also, as θ varies from 0 to 2π, the point P (Fig 10 28) traces the circle x2 + y2 = 1
counterclockwise, and this covers all possible directions So, (1) gives every unit vector
in the XY-plane © NCERT
not to be republished
 MATHEMATICS
456
Example 27 If 
ˆ
ˆ
ˆ
ˆ
ˆ
ˆ
ˆ
ˆ
ˆ
ˆ
ˆ
, 2
5 , 3
2
3   and  
6
 
 
 
 
 
 
i
j
k
i
j
i
j
k
i
j
k  are the position
vectors of points A, B, C and D respectively, then find the angle between AB
uuur
 and
CD
uuur