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Re: Re: New user: Abs[] problem

  • To: mathgroup at smc.vnet.net
  • Subject: [mg50100] Re: Re: [mg50079] New user: Abs[] problem
  • From: Bob Hanlon <hanlonr at cox.net>
  • Date: Sun, 15 Aug 2004 03:14:26 -0400 (EDT)
  • Reply-to: hanlonr at cox.net
  • Sender: owner-wri-mathgroup at wolfram.com

You get a complete result with Reduce

eqn=x+1-Abs[2x-4]+Abs[5-x]==0;

Reduce[eqn,x]

x == -1 || Re[x] >= 5 && Im[x] == 0

Reduce[eqn,x, Reals]

x == -1 || x >= 5

Plot[x+1-Abs[2x-4]+Abs[5-x],{x,-2,8}, PlotRange->All, 
    PlotStyle->RGBColor[1, 0, 0]];


Bob Hanlon
> 
> From: Bob Hanlon <hanlonr at cox.net>
To: mathgroup at smc.vnet.net
> Date: 2004/08/14 Sat AM 09:54:33 EDT
> To: <Edson.Brusque at smc.vnet.net>, <mathgroup at smc.vnet.net>
> Subject: [mg50100] Re: [mg50079] New user: Abs[] problem
> 
> eqn=x+1-Abs[2x-4]+Abs[5-x]==0;
> 
> FindRoot[eqn,{x,2}]
> 
> {x -> 5.}
> 
> eqn /. %
> 
> True
> 
> 
> Bob Hanlon
> 
> > 
> > From: Edson.Brusque at smc.vnet.net
To: mathgroup at smc.vnet.net
> > Date: 2004/08/14 Sat AM 01:50:33 EDT
> > To: mathgroup at smc.vnet.net
> > Subject: [mg50100] [mg50079] New user: Abs[] problem
> > 
> > Hello,
> > 
> >      I'm starting Electrical Engineering and using Mathematica for 
> > helping me in Calculus e Algebra studies.
> > 
> >      I'm trying to solve this equation on Mathematica:
> >          x + 1 - |2x - 4| + |5 - x| = 0
> > 
> >      on the Math* notebook I'm typing:
> >          Solve[x + 1 - Abs[2x - 4] + Abs[5 - x] == 0,x]
> > 
> >      but only got an empty output: {{}}
> > 
> >      Someone please can help me get Math* to solve this?
> > 
> >      Thank you very much,
> > 
> >      Edson Brusque
> > 
> > 
> 
-----------------------------------------------------------------
> ----
> > Edson Brusque                     C.I.Tronics Lighting Designers Ltda
> > Research and Development                   Blumenau  -  SC  -  Brazil
> > http://www.suporte.ind.br/ryan/netiqueta.htm     www.citronics.com.br
> > 
> 
-----------------------------------------------------------------
> ----
> > 
> > 
> > 
> > 
> 

Bob Hanlon
Chantilly, VA


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