Question
Find the shortest distance between the following lines.
and 
Solution
The equations of the two lines are
...(1)
and 
...(2)
Comparing these equations with
Let S be point on line (1) with position vector 
and T be point on line (2) with position vector 
so that
Now, 
Let 
be the S.D. vector between given lines. Therefore, it is parallel to 
If 
is a unit vector along 
, then
Now, S.D. = 
