MathGroup Archive 2008

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Solve[] doesn't

  • To: mathgroup at smc.vnet.net
  • Subject: [mg90635] Re: [mg90619] Solve[] doesn't
  • From: Sseziwa Mukasa <mukasa at jeol.com>
  • Date: Thu, 17 Jul 2008 05:34:15 -0400 (EDT)
  • References: <200807161029.GAA08789@smc.vnet.net>

On Jul 16, 2008, at 6:29 AM, Hauke Reddmann wrote:

> This is extremely annoying.
> I have a very large (this seems to be critical) equation
> system. It's partly linear, partly horror, but already
> after I solve the linear part, a certain solution (which
> is obviously one since substituting it in makes all equations
> identical zero) can't be found anymore. The solution has some
> surds (this also seems critical, the ones without are found)
> but the equations are strictly polynomic.
>
> Faked Example (the real one only PM-ed, since it's a bit
> oversized):
>
> x-y=1
> x^2+y^2=3
> x^3-y^3=4
> and after y was eliminated, it doesn't find x. (=golden mean here)
>
> Huh?

The system has no problems for me:

In[9]:= Solve[{x-y==1,x^2+y^2==3,x^3-y^3==4},{x,y}]
Out[9]= {{x->1/2 (1-Sqrt[5]),y->1/2 (-1-Sqrt[5])},{x->1/2 (1+Sqrt 
[5]),y->1/2 (-1+Sqrt[5])}}

Your problem would probably be clearer if you used Mathematica notation.

Regards,

Ssezi



  • Prev by Date: Re: Solve[] doesn't
  • Next by Date: Re: Formatting Plot Legends
  • Previous by thread: Re: Solve[] doesn't
  • Next by thread: Re: Solve[] doesn't