[newbie question] solving fifth order polynomial equation

On 1/17/07, sen1 at math.msu.edu <sen1 at math.msu.edu> wrote:
> It seems that "realroots" with no other argument gives rational
> solutions....
> I presume, but did not check, that this means that the roots are
> rational.
> Or, are these just approximate values?

They are approximate values.  Realroots uses rational arithmetic to
support variable precision -- that is, as the Sturm sequence is
evaluated, it is using more and more precision.  This could be done
with bfloats, but a) bfloats didn't exist when realroots was written
and b) varying the precision is messy and not very efficient.  It
would probably make sense, on the other hand, to return the values as
bfloats of appropriate precision.

          -s