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Re: "Rubbish" integration outputs

• To: mathgroup at smc.vnet.net
• Subject: [mg45732] Re: "Rubbish" integration outputs
• From: drbob at bigfoot.com (Bobby R. Treat)
• Date: Thu, 22 Jan 2004 03:37:32 -0500 (EST)
• References: <bulomk$8ir$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Solutions given by DSolve sometimes include integrals that cannot be
carried out explicitly by Integrate. Dummy variables with local names
are used in such integrals.

It's ugly, I agree.

Bobby

"Iwonder" <yssual at yahoo.com> wrote in message news:<bulomk$8ir$1 at smc.vnet.net>...
> Hi,
> 
> I always find me in troubles when integrating ODE that I think Mathematica
> should be able to do. It's all right for the very simplest, but consider for
> instance the following:
> 
> \!\(DSolve[\((x + 2  x\^2 + x\^3)\) \(y'\)[x] + \(x\^2\) \(y''\)[x] == A, y,
>     x]\)
> 
> 'A' a constant. Well, the problem is that I don't even the clue that
> Mathematica *cannot* integrate it, there is some output with gibberish, like
> K$14646 and the like (those are intermediary variables I guess). So what is
> wrong? Is Mathematica expected to return such outputs?
> 
> Cheers.