[sage-devel] Doctest failure solving an equation solve(Q*sqrt(Q^2 + 2) - 1, Q)
- Subject: [sage-devel] Doctest failure solving an equation solve(Q*sqrt(Q^2 + 2) - 1, Q)
- From: Robert Dodier
- Date: Sun, 9 Aug 2009 19:59:49 -0600
On 8/9/09, Barton Willis <willisb at unk.edu> wrote:
> $ ./maxima-local
> Maxima 5.18post http://maxima.sourceforge.net
>
> (%i2) load("to_poly_solver.mac")$
> (%i3) display2d : false$
>
> (%i4) to_poly_solve(q*sqrt(q^2+2)-1,q);
> (%o4) %union([q = -1/sqrt(1-sqrt(2))],[q = 1/sqrt(1-sqrt(2))],[q = 1/sqrt
> (sqrt(2)+1)])
Unfortunately this isn't right either. The first solution is spurious, isn't it?
float(subst(q = -1/sqrt(1-sqrt(2)), q*sqrt(q^2+2)-1)) => - 1.999999999999999
Thanks for your help
Robert Dodier