       Re: rewriting a fraction a/b==c/d + e/f

• To: mathgroup at smc.vnet.net
• Subject: [mg31007] Re: rewriting a fraction a/b==c/d + e/f
• From: "Allan Hayes" <hay at haystack.demon.co.uk>
• Date: Tue, 2 Oct 2001 01:20:42 -0400 (EDT)
• References: <9p93dn\$oce\$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

```Okke,

Apart[1/((x-1)(x^2+x+1))]

1/(3*(-1 + x)) + (-2 - x)/(3*(1 + x + x^2))

In this case, the Help Browser helps:
- select Partial Fractions

Also

SolveAlways[1/((x-1)(x^2+x+1))== A/(x-1) + (B x+C)/(x^2+x+1),x]

{{A -> 1/3, B -> -(1/3), C -> -(2/3)}}

A/(x-1) + (B x+C)/(x^2+x+1)/.%[]

1/(3*(-1 + x)) + (-(2/3) - x/3)/(1 + x + x^2)

--
Allan
---------------------
Allan Hayes
Mathematica Training and Consulting
Leicester UK
www.haystack.demon.co.uk
hay at haystack.demon.co.uk
Voice: +44 (0)116 271 4198
Fax: +44 (0)870 164 0565

"Okke" <kroosu at tref.nl> wrote in message news:9p93dn\$oce\$1 at smc.vnet.net...
> hello,
> i'm trying the mathematica demo by doing some basic mathematics.
> now i'm stuck at rewritting a fraction.
>
> 1/((x-1)(x^2+x+1)) to A/(x-1) + (Bx+C)/(x^2+x+1)
> or do i have to do that manualy?
> and can mathematica find  the values for A, B and C ?
> Solve[eqn1==eq2,{A}] doesnt solve the problem, and subsituting
> x with 1 doesnt either.
>
> tia,
> --
> Okke <kroosu at tref.nl>
>

```

• Prev by Date: Re: help: rewriting a fraction a/b==c/d + e/f
• Next by Date: Parallel Processing Toolkit
• Previous by thread: Re: rewriting a fraction a/b==c/d + e/f
• Next by thread: Re: how do you solve a less-or-equal equation