Re: Solve question
- To: mathgroup at smc.vnet.net
- Subject: [mg57466] Re: [mg57457] Solve question
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Sun, 29 May 2005 01:03:25 -0400 (EDT)
- Reply-to: hanlonr at cox.net
- Sender: owner-wri-mathgroup at wolfram.com
eqn=a*x^2+b*x+c==0;
soln=Solve[eqn,x]
{{x -> (-b - Sqrt[b^2 - 4*a*c])/(2*a)},
{x -> (Sqrt[b^2 - 4*a*c] - b)/(2*a)}}
The result is a set of rules, {lhs -> rhs}. Rules are used with Replace,
ReplaceAll ( /. ), or ReplaceRepeated ( //. ). For example, verifying that the
solutions satisfy the original equation:
eqn/.soln //Simplify
{True,True}
Bob Hanlon
>
> From: "Sterritt, Lanny" <lanny.sterritt at lmco.com>
To: mathgroup at smc.vnet.net
> Date: 2005/05/28 Sat AM 05:39:41 EDT
> Subject: [mg57466] [mg57457] Solve question
>
> When the Solve command is used to obtain the value of a variable in an
equation, something like {x -> value} is returned. How does one get
Mathematica to automatically apply this value to following expressions in a
notebook?
>
> L.W.Sterritt
>
>