Re: Setting up equations
- To: mathgroup at smc.vnet.net
- Subject: [mg66038] Re: Setting up equations
- From: dh <dh at metrohm.ch>
- Date: Thu, 27 Apr 2006 04:36:29 -0400 (EDT)
- References: <e2nd3i$33m$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi Yaroslav,
you could transform your expression into the null polynomial and extract
coefficents of x,y,z. E.g.:
eq1=5 x + 6 y + 7 z == a x + b y + c z
eq2= Subtract @@ eq1
Extracting coefficients:
cof= Coefficient[eq2,{x,y,z}]
and putting them into an new equation:
(# == 0) & /@ cof
this yields a list of equation that you may solve by Solve or Reduce
Daniel
Yaroslav Bulatov wrote:
> I'm trying to do things of the form
> Solve[5 x + 6 y + 7 z == a x + b y + c z, {a, b, c}]
>
> But since x,y,z are variables, what I really mean is
> Solve[5==a && 6==b && 7==c], so I need to convert to this form
>
> If I only have one variable, the following does what I need
>
> LogicalExpand[a*x + b*x^2 + O[x]^3 == 2*x + 3*x^2 + O[x]^3]
>
> But what to do if I have several variables?
>