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.