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Re: How to isolate the constant in a two variable equation?

• To: mathgroup at smc.vnet.net
• Subject: [mg113484] Re: How to isolate the constant in a two variable equation?
• From: "Eduardo M. A. M.Mendes" <emammendes at gmail.com>
• Date: Sat, 30 Oct 2010 04:39:28 -0400 (EDT)

Hello

Many many thanks.  It worked fine but I had to use Expand before issuing the
command.

Cheers

Ed

From: Thomas Dowling [mailto:thomasgdowling at gmail.com] 
Sent: Friday, October 29, 2010 9:06 AM
To: Eduardo M. A. M.Mendes
Subject: [mg113484] Re:  How to isolate the constant in a two variable
equation?

 

Hello,

expr = 4 X*X + 3 Y*Y + 2 X*Y + 1

Select[expr, FreeQ[#, _Symbol] &]
or
Select[expr, FreeQ[#, X | Y] &]

is the way I would do it.  Tom Dowling 

On Fri, Oct 29, 2010 at 11:30 AM, Eduardo M. A. M.Mendes
<emammendes at gmail.com> wrote:

Hello



I know that Coefficient can isolate the coefficient relate to the variables
in an equation but I wonder how the constant could be retrieved.



Something like



 4X*X+3Y*Y+2X*Y+1



How to get to isolate the constant 1?



Many thanks



Ed