Write a unit vector in the direction of 
, where P and Q are the points (1, 3, 0) and (4, 5, 6) respectively.
If the co-ordinates of points A≡ (x1, y1, z1) and B≡ (x2, y2, z2), then the vector 
is
Given that P≡(1,3,0) and Q≡(4,5,6), we get
The unit vector of any vector 
can be written as 
Hence, 
1