[GAP Forum] minimal polynomes

[Burkhard Höfling]

On 2011-12-06, at 23:05 , Lisette Brillemans wrote:

> Dear all,
> 
> I have been looking but couldn’t find it.
> Does GAP have a function to compute the minimal polynomial for a given algebraic number?
> 
> So I’m looking for something like MinimalPolynomial(sqrt(3)+2);
> and that GAP answers then: x^2-4x+1.

To define a minimal polynomial, you have to specify the admissible coefficient field. In your case, it's 
the rationals, apparently, so just use

gap> MinimalPolynomial (Rationals, Sqrt(3)+2);
x_1^2-4*x_1+1

Cheers

Burkhard.