Solving polynomials with Maxima ?



Thanks for your answers, it really helped !

Laure
                                   

 

 
 

 


There is no need to recycle if you don?t print this e-mail.



"W F" <amzoti at gmail.com> 
Sent by: maxima-bounces at math.utexas.edu
22/09/2008 06:36 PM

To
fateman at cs.berkeley.edu
cc
Maxima Mailing List <maxima at math.utexas.edu>, Laure.DUTOIT at cepal.org
Subject
Re: [Maxima] Solving polynomials with Maxima ?






Maybe the last file was too large.

Here is the real solution - but there are two imaginary ones too.



On Mon, Sep 22, 2008 at 3:19 PM, W F <amzoti at gmail.com> wrote:
I also solved it in Mathematica and added a jpg file of the output.

It looks like there us a real and two imaginary solutions.

Not sure that helps.

~A

On Mon, Sep 22, 2008 at 3:16 PM, Richard Fateman <fateman at cs.berkeley.edu> 
wrote:
Your "polynomial" is of degree 3 in x^(1/2).
 
I suggest you make the change of variables t=x^(1/2) and solve
 
a*t^3-b*t^2+c*t-d=0.
 
This can be solved for t by solve(......,t);
 
then take the square root of the answer. This will give you 6 solutions (+ 
and - sqrt).
 
I hope this helps.
 
(The symbolic solution to a cubic like this is generally very complicated 
and not of much use.)
 
 

From: maxima-bounces at math.utexas.edu [mailto:
maxima-bounces at math.utexas.edu] On Behalf Of Laure.DUTOIT at cepal.org
Sent: Monday, September 22, 2008 3:10 PM
To: maxima at math.utexas.edu
Subject: Solving polynomials with Maxima ?


Dear all, 

I am trying to solve a polynomial using Maxima, but I cannot get an 
explicit answer. My polynomial is of the following form: 
x^(3/2) a - x b + x^(1/2) c - d =0, where a,b,c and d are composed of 
several variables, but are not of interest. 

So, I would like to be able to solve this polynomial (I am not a 
mathematician, but I think solving such a polynomial is feasible using a 
mathematical software, no ?) using Maxima to get to an answer of the form 
x=f(a,b,c,d) and not x=f(a,b,c,d,x), as I now get using the command 
"solve" (i.e, the answer I am given is not explicit). 

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