MathGroup Archive 2000

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

Search the Archive

Re: Arithmetic simplification

  • To: mathgroup at
  • Subject: [mg26222] Re: Arithmetic simplification
  • From: "Paul Lutus" <nospam at>
  • Date: Sun, 3 Dec 2000 18:05:54 -0500 (EST)
  • References: <90a7o4$>
  • Sender: owner-wri-mathgroup at

"Adalbert Hanssen" <hanssen at> wrote in message
news:90a7o4$e8t at
> Hi, MathGroup,
> why does Mathematica return this sample expression unchanged
> (it can easily be simplified to 0, as the second
> part is just the first half with 1/3 factored out)?
> o30/3+(dw2*o46)/(3*o55)+o55/(3*dw2) - (o30+(dw2*o46)/o55+o55/dw2)/3
> Of course, in this case Simplify, Expand or Together
> find, that this is 0. This is only a sniplet from
> a larger expression with a dozen of ohter variables,
> indeed, o33, o46 and o55 are themselves expressions
> involving several other variables.
> I tried to simplify the large expression by hand
> (i.e. factor out common factors from partial sums
> etc) and I used Mathematica to check, if I did it
> right. However, in several cases, Together,
> PowerExpand and Simlify took "forever" after
> I did simplifications of the above kind.
> Is there a way to first apply Together etc
> only to Arguments of Sqrt, Power etc,
> in particular first to those Sqrt, Power etc,
> which are nested most deeply and apply thm
> to the higher ones after that?

I'd like to be able to help you, but Mathematica 4.0's result is:

Simplify[o30/3 + (dw2*o46)/(3*o55) +
    o55/(3*dw2) - (o30 + (dw2*o46)/o55 + o55/dw2)/3]


I guess it helps to include the version of Mathematica you are using. :)

Paul Lutus

  • Prev by Date: Volumes
  • Next by Date: Integrating Conditionals/piecewise cont. functions
  • Previous by thread: Arithmetic simplification
  • Next by thread: Re: Arithmetic simplification