A transformation may be represented by a matrixoperating on a vector
where
is the position vector of a point P. The resulting transformed position vector is
It is important to note that the position of the pointdoes not change in space, only the representation of the point with respect to the new coordinate system. We may consider the matrix acting to change the basis of the space into a new basis.
Suppose the transformation T is represented by the matrixIf the original coordinate system has basis vectors
called the standard basis
then the transformed basis vectors are given byand
We may write a point with position vectoras
We can find a similar representation in the new coordinate system for a vectorin terms of
and
Suppose we have a vectorWe can write
so
Hence
This is general. If the matrix representing a change of basis isthe basis vectors
and
transform as
and
but the components
and
transform as
and
respectively.