Express the matrix
(whose entries are in Q [ X ] ⊂ Q ( X ) {\displaystyle {}\mathbb {Q} [X]\subset \mathbb {Q} (X)} ) in the form
with matrices A 4 , A 3 , A 2 , A 1 , A 0 ∈ Mat 2 ( Q ) {\displaystyle {}A_{4},A_{3},A_{2},A_{1},A_{0}\in \operatorname {Mat} _{2}(\mathbb {Q} )} .
![{\displaystyle {}\mathbb {Q} [X]\subset \mathbb {Q} (X)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/de5debe585f545a8e56ade913cf0d2e9bf9912ac)
)
in the form
.
