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## Re: [Axiom-developer] Re: partfrac, expand, combine, rewrite and simplif

 From: Dylan Thurston Subject: Re: [Axiom-developer] Re: partfrac, expand, combine, rewrite and simplify. Date: Tue, 7 Oct 2003 12:24:48 -0400 User-agent: Mutt/1.5.4i

```On Tue, Oct 07, 2003 at 10:19:14AM -0400, Tim Daly wrote:
> > // 2 //
> > I call partfrac the transform as 2x^3 / (1-x^2) = 1/(1-x) - 1/(1+x) - 2x
> >
> > What is its name in axiom ?
>
> The partialFraction function will create a partial fraction thus:
>
> -> partialFraction(7,12)
>
>        3   1
>   1 - -- + -
>        2   3
>       2
>                   Type: PartialFraction Integer

Right, but this doesn't help with the actual problem!  Apparently to
convince partialFraction to work on polynomials you need to provide some
type information.

Furthermore, I think there's a bug here:

------
(8) -> partialFraction((2*x^3), (1-x^2))
There are 1 exposed and 1 unexposed library operations named
partialFraction having 2 argument(s) but none was determined to
be applicable. [snippage]
(8) -> partialFraction((2*x^3)::UP(x, FRAC INT), (1-x^2))

2x
(8)  - 2x - ------
2
x  - 1
Type: PartialFraction UnivariatePolynomial(x,Fraction Integer)
(9) -> partialFraction((2*x^3), (1-x^2)::UP(x, FRAC INT))

1       1
(9)  - 2x - ----- - -----
x - 1   x + 1
Type: PartialFraction UnivariatePolynomial(x,Fraction Integer)
------

Why didn't input (8) above actually do the partial fraction expansion?

Peace,
Dylan
```

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