In the 3D coordinate system, lines can be described using vector
equations or parametric equations. Lines in 3D have equations
similar to lines in 2D, and can be found given two points on the
line. In order to understand lines in 3D, one should understand
how to parameterize a line in 2D and write the vector equation
of a line. Perpendicular, parallel and skew lines are important
cases that arise from lines in 3D. One of the great things about
the vector equation of a line is that the same equation applies
in 2 dimensions as in 3 dimensions so that's our goal today is
to come up with equations for lines and 3 dimensions. 3
dimensions as a vector equation is the same as in 2D here is a
picture of a line in 3D all we need to know is the position
vector of 1 point on the line and a direction vector that
indicates the direction of the line and then the equation for
the line will be r vector r equals r0 plus some constant times v
the direction vector. So all we need is one position vector and
a direction vector an