Learn how to show that three points lie in a line (collinear) using vectors

Showing that three points lie in a straight line (i.e. collinear) is a straight-forward process. It can be achieved using gradients or vectors. In this video I explain the vector method which is essentially about showing that two vectors are parallel. If you’re not familiar with vectors at all it would be useful to learn some basic ideas before taking on this technique. Any questions about this video drop us a message HERE.

Key Points

Collinear refers to points laying in a straight line

Collinearity can be shown using vectors or gradients

Using gradients we show the vectors are parallel and share a point

Vectors are parallel if one is a multiple of the other

Points can be collinear but there are no collinear vectors

Learn more about our LINEAR ALGEBRA course here