transformation matrix
suppose that
and
are finite-dimensional vector spaces with ordered bases
and
, respectively. let
be linear. then for each
, there exist unique scalars
, such that
we call the
matrix
defined by
the matrix representation of
in the ordered bases
and
and write
. if
and
, then we write 
[cite:;taken from @algebra_insel_2019 chapter 2 linear transformations and matrices]
notice that the [cite:;taken from @algebra_insel_2019 chapter 2 linear transformations and matrices]
[cite:;taken from @algebra_insel_2019 chapter 2 linear transformations and matrices]
let
, and
be finite-dimensional vector spaces with ordered basis
, and
, respectively. let
and
be linear transformations. then
[cite:;taken from @algebra_insel_2019 theorem 2.11]
the following theorem states that if we want to find the coordinates of the transformed vector let
and
be finite-dimensional vector spaces having ordered bases
and
, respectively, and let
be linear. then, for each
, we have
[cite:;taken from @algebra_insel_2019 theorem 2.14]
let
such that

is given by
more generally, we want to have
such that
we have
and
which means

when the transformation matrix is from the basis onto itself, we may denote it by
. we have 
the relation between
and
:
which means
then

let
that is defined by
, let
and
be 2 bases of
.
- find
,
- find
.
solution steps:
- change-of-basis matrices (
,
): these are the tools for translating between bases.
- single-basis transformation matrices (
,
): these represent the transformation
if you work exclusively in one basis.
- mixed-basis transformation matrices (
,
): these represent
when moving from one basis to another.
- change-of-basis matrices
first, we find the matrix
which converts coordinates from basis
to basis
. its columns are the coordinate vectors of
expressed in basis
.
this gives the change-of-basis matrix from
to
:
the change-of-basis matrix from
to
is its inverse:
- single-basis transformation matrices
next, we find
. we apply
to each vector in
and find the coordinates of the result relative to
.
assembling the columns gives
:
now we find
using the change-of-basis formula
:
- mixed-basis transformation matrices
the matrix
takes a vector in
, applies
, and gives the result in
. we find it by first transforming in
(
), then translating the result to
(
).
similarly,
takes a vector in
, applies
, and gives the result in
. we transform in
(
), then translate to
(
).
let
be a linear operator on a finite-dimensional vector space
, and let
and
be ordered bases for
. suppose that
is the change of coordinate matrix that changes
-coordinates
into
-coordinates. then
[cite:;taken from @algebra_insel_2019 theorem 2.23]
into