Question
Find the shortest distance (S.D.) between the lines:
Solution
The equation of two lines are
...(1)
and
...(2)
Comparing these equations with
Let S be a point on line (1) with position vectors
be point on line (2) with position vectors 
so that
Let
be S.D. vector between given lines.
it is parallel to 
If 
is unit vector along 
, then
NOW S.D. = Projection of ST on
= Projection of ST on
...(1)and
...(2)Comparing these equations with
Let S be a point on line (1) with position vectors
be point on line (2) with position vectors so thatLet
be S.D. vector between given lines. it is parallel to If is unit vector along , thenNOW S.D. = Projection of ST on
= Projection of ST on
