Question
Determine whether the following pair of lines intersect:

and 
Solution
The equations of two lines are
...(1)
and
...(2)

Comparing these equations with
and 

Let S be points on line (1) with position vector
and T be point on limit (2) with position vector
so that


Let
be the S.D. vector between given lines. Therefore, it is parallel to 
If
is a unit vector along
then

Now S.D. = Projection of


∴ given lines do not interesect.

and


Comparing these equations with



Let S be points on line (1) with position vector




Let


If



Now S.D. = Projection of



∴ given lines do not interesect.