Shortest distance between two straight lines
Three Dimensional Geometry of Class 12
Shortest distance between two straight lines
Skew Lines
Two straight lines in space which are neither parallel nor intersecting are called skew lines.
Line of shortest distance
If l1 and l2 are two skew lines, then there is one and only one line perpendicular to each of lines l1 and l2 which is known as the line of shortest distance.
Shortest distance
The shortest distance between two lines l1 and l2 is the distance PQ between the points P and Q where the lines of shortest distance intersects the two given lines.
Vector form
If 
and 
are two skew lines, then the shortest distance between these lines is d = 
Cartesian Form
Let 
and 
are two skew lines, then shortest distance between these lines is given by
d = 
