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Re: Re: Getting rid of the symbol -> after finding the root

  • To: mathgroup at smc.vnet.net
  • Subject: [mg39360] Re: [mg39326] Re: Getting rid of the symbol -> after finding the root
  • From: Kirk Reinholtz <kirk.reinholtz at jpl.nasa.gov>
  • Date: Wed, 12 Feb 2003 03:53:44 -0500 (EST)
  • References: <200302110942.EAA26084@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

You'll want to read about "Rule" in the help browser: Understanding this
construct is critical to your understanding of Mathematica.

When you have an output like a->3, you can use that rule to (say)
replace all instances of "a" in an expression with "3".  For example,
a x + 7 /. {a->3}
will replace the "a" with "3".  This operation is quite general, vastly
more powerful than you might imagine by this simple example.

If you just want to "remove" the "->", then 

r={a->3}
a/.r

will do as you wish.
"Mostaghel, Naser" wrote:
> 
> Dear Friends,
> I need to use the root of a simple equation in subsequent operations.
> After extracting the root, it comes in the form ->root.  I have not been
> able to get rid of the symbol -> .
> 
> Can someone help?
> 
> Thanks,
> 
> Naser Mostaghel
> Professor, Civil Engineering
> T: (419) 530-8131
> F: (419) 530-8116
> E: nmostag at utnet.utoledo.edu


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