Unit vector

vector of length one

A unit vector is any vector that is one unit in length.

Unit vectors are often notated the same way as normal vectors, but with a mark over the letter (e.g. is the unit vector of a.)

To make a vector into a unit vector, divide it by its length:

In component formEdit

Three common unit vectors used in component form are  ,   and  , referring to the unit vectors for the x-, y- and z-axes respectively. They are commonly just notated as i, j and k.

They can be written as the following: