fraction manipulations



      taylor(1/(A*B)+1/(AC)+1/(A^2*E)+1/(A^2*D), A, 0, 3);
 
gives the exact result
 
      (E+D)/(D*E*A^2)+1/(B*A)+1/AC+...,
 
after which you can probably manually or programmatically isolate the coefficients of the powers of A, then expand those coefficients into partial fractions or whatever you want.
 
-- best regards, david stoutemyer

----- Original Message -----
From: Dmitry Shkirmanov <piminusmeson at bk.ru>
Date: Wednesday, December 14, 2011 6:49 am
Subject: Re: [Maxima] fraction manipulations
To: maxima at math.utexas.edu

> On 14.12.2011 17:45, Rupert Swarbrick wrote:
> > Dmitry Shkirmanov<piminusmeson at bk.ru>  writes:
> >    
> >> Hello, list. Is there any function in maxima, that can
> >> 1/(A*B)+1/(AC)+1/(A^2*E)+1/(A^2*D) rewrite into
> >> 1/A*(1/B+1/C)+1/A^2*(1/D+1/E) ?
> >>      
> >   Frankly, I don't see the point though: after
> > all, what are you going to do with the result? As soon as you 
> touch it
> > with any other computation, it'll get re-simplified in a way 
> you don't
> > recognise...
> >
> >    
> Thanks for help.
> 
> I will try to explain why i need this. I have an expression, 
> that contains different powers of "A". The simplest example of 
> such expression is:
> 
> 1/(A*B)+1/(AC)+1/(A^2*E)+1/(A^2*D)     (But 
> it can contain terms like 1/A^3, 1/A^4 and so on)
> 
> in my case, "B","C","E","D" is some complicated expressions.
> 
>   . I know, that "A" is big, so i want to get power series 
> expansion, like 1/A*(some_expression) + 1/A^2*(other_expression)+...
> After this, i want to study "some_expression", "other 
> expression" separately.
> 
> P.S. Sorry for my rough english
> 
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