### 2.12.6 Canonical form : `canonical_form`

`canonical_form` takes as argument a trinomial of second
degree.

`canonical_form` returns the canonical form of the argument.

Example :

Find the canonical form of :

Input :

`canonical_form(x``^`

`2-6*x+1)`

Outpout :

`(x-3)``^`

`2-8`