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

Re: Simplify expression

• To: mathgroup at smc.vnet.net
• Subject: [mg57804] Re: Simplify expression
• From: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>
• Date: Thu, 9 Jun 2005 05:17:36 -0400 (EDT)
• Organization: Uni Leipzig
• References: <d8697g$c9t$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Hi,

you can't because Sqrt[[(x1^2-x2^2)^2] is 
Abs[x1^2-x2^2]

Regards
  Jens

"Mukhtar Bekkali" <mbekkali at gmail.com> schrieb im 
Newsbeitrag news:d8697g$c9t$1 at smc.vnet.net...
>I need to solve system of equations 
>f1[x1,x2]=0,f2[x1,x2]==0, however,
> some elements of these equation have the form 
> Sqrt[(x1^2-x2^2)^2].  It
> takes really long time to solve.  If, however, I 
> manually simplify
> those elements, for example, 
> Sqrt[(x1^2-x2^2)^2]=x1^2-x2^2 then solve
> is fast.  Therefore, the question is how I can 
> force mathematica
> simplify expressions of this sort (another 
> elements are fractions that
> depend on x1 and x2 in Mathematica's mind but in 
> reality they cancel
> out and fraction becomes a number). I do not 
> want to use FindRoot since
> I want to see all solutions. Thanks, Mukhtar 
> Bekkali
>