Straight Line in Space
Three Dimensional Geometry of Class 12
STRAIGHT LINE IN SPACE
Equation of straight line
Line passing through a given point
Vector equation of a straight line passing through a fixed point (with position vector 
) and parallel to a given vector 
is 
= + λ, where λ is a scalar.
The cartesian equation of a straight line passing through a fixed point (x1, y1, z1) and having direction ratios a, b, c is 
= 
= 
.
Line passing through two given points
The vector equation of line passing through two given points (with position vector and ) is 
.
The Cartesian equation of a line passing through two given points (x1, y1, z1) and (x2, y2, z2) is given by 
.
