to_poly_solve regression
- Subject: to_poly_solve regression
- From: Barton Willis
- Date: Fri, 26 Jun 2009 18:45:39 -0500
The new solver is to_poly_solver, not topoly_solver. The to_poly_solve
function in 5.18.1 might have a bug that keeps it from solving this
equation. The CVS version gives three solutions, but I think one
solution is spurious :(
(%i2) load("to_poly_solver")$
(%i3) to_poly_solve(Q*sqrt(Q^2 + 2) - 1 = 0,Q);
(%o3) %union([Q = -1/sqrt(1-sqrt(2))],[Q = 1/sqrt(1-sqrt(2))],
[Q = 1/sqrt(sqrt(2)+1)])
(%i4) float(%);
(%o4) %union([Q = 0.643594252905583],[Q = -1.553773974030037*%i],
[Q = 1.553773974030037*%i])
(%i5) makelist(subst(sx, Q * sqrt(Q^2 + 2)-1),sx, args(%));
(%o5) [0.0,-8.881784197001252E-16,-1.999999999999999]
(%i6)
Barton
-----maxima-bounces at math.utexas.edu wrote: -----
>To:?maxima?<maxima at math.utexas.edu>
>From:?Mike?Hansen?<mhansen at gmail.com>
>Sent?by:?maxima-bounces at math.utexas.edu
>Date:?06/26/2009?04:51PM
>Subject:?[Maxima]?to_poly_solve?regression
>
>Hello,
>
>In?Maxima?5.16.3,?we?get?two?solutions:
>
>(%i1)?load(topoly_solver);
>(%o1)?/opt/sage/local/share/maxima/5.16.3/share/contrib/topoly_solver.mac
>(%i2)?to_poly_solve(Q*sqrt(Q^2?+?2)?-?1?=?0,?Q);
>????????????????????????????1????????????????????????1
>(%o2)?????????[[Q?=?-----------------],?[Q?=?-----------------]]
>????????????????????sqrt(1?-?sqrt(2))????????sqrt(sqrt(2)?+?1)
>
>In?Maxima?5.18.1,?we?get?just?one:
>
>(%i3)?load(topoly_solver);
>(%o3)
>
>/opt/sage-4.0.2.rc2/local/share/maxima/5.18.1/share/contrib/topoly_solver.
>mac
>(%i4)?to_poly_solve(Q*sqrt(Q^2?+?2)?-?1?=?0,?Q);
>
>
>?????????????????????????????????????????1
>(%o4)??????????????????????[[Q?=?-----------------]]
>?????????????????????????????????sqrt(sqrt(2)?+?1)
>
>--Mike
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