Re: [fricas-devel] Re: Selection of roots

Alejandro Jakubi <[email protected]> Mon, 3 Nov 2008 20:21:27 -0300
Newsgroups gmane.comp.mathematics.axiom.general,gmane.comp.mathematics.open-axiom.devel
Message-ID <Pine.WNT.4.64.0811032000570.2608@usuario-de5f78f>
On Mon, 3 Nov 2008, Martin Rubey wrote:

> Alejandro Jakubi <[email protected]> writes:
>> Now, my next question is about selecting the two real roots out of the four
>> produced by 'radicalSolve' here:
>>
>> f:=(x^3+x^2-4*x-4)/(2*x^2+7*x-4)
>> fp:=differentiate(f,x)
>> radicalSolve(fp,x)
>>
>> The problem is that
>>
>> allRootsOf(fp)$RealClosure(Fraction Integer)
>
> try
>
> allRootsOf(numer fp)$RealClosure(Fraction Integer)
>

Fine. Now, how I recover the algebraic expressions, as produced by
'radicalSolve', associated with such labels like %A1, %A2 ?


Alejandro Jakubi