MathGroup Archive 2000

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: algebraic manipulation

  • To: mathgroup at smc.vnet.net
  • Subject: [mg22379] Re: [mg22349] algebraic manipulation
  • From: "David Park" <djmp at earthlink.net>
  • Date: Sat, 26 Feb 2000 22:05:07 -0500 (EST)
  • Sender: owner-wri-mathgroup at wolfram.com

Peter,

I believe that the expression you intended does automatically simplify:

k*r*Cos[k*r]/(Sqrt[k]*r^3)
(Sqrt[k]*Cos[k*r])/r^2

But it looks like you are using {} where you should be using [] or (). If you are in
StandardForm then [] is for function arguments, () is for grouping, and {} is for
Lists in any Form. So it is most likely that you have entered the expression
incorrectly.

David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/

>sorry to ask such a simple question...
>
>i have a very long espression of the form
>
> A[k, r]( B[k,r] + C[k,r] + blah blah blah)
> ------------------------------------------
>             D[k, r]
>
>it took me awhile to figure out how to decompose this (i was trying to use
>Apart.  instead, ExpandAll seemed to do the trick).
>
>but i'm still seeing terms that look like:
>
>   k r cos(k r)
>   -------------
>   \sqrt{k} r^{3}
>
>no amount of coaxing seems to make Mathematica want to reduce this to:
>
>   \sqrt{k} \cos(k r)
>   ------------------
>          r^{2}
>
>FullSimplify just undoes ExpandAll and puts everything over a common
>denominator.   i want separate terms which are fully reduced.
>
>how can i have Mathematica aggresively reduce these individual terms?
>
>thanks!
>pete
>
>
>



  • Prev by Date: Re: Using user-defined functions (newbie question)
  • Next by Date: Re: algebraic manipulation
  • Previous by thread: Re: algebraic manipulation
  • Next by thread: Re: algebraic manipulation