Re: Simplfying inside Sqrt

• To: mathgroup at smc.vnet.net
• Subject: [mg55131] Re: [mg55106] Simplfying inside Sqrt
• From: Chris Chiasson <chris.chiasson at gmail.com>
• Date: Sun, 13 Mar 2005 04:57:53 -0500 (EST)
• References: <200503120736.CAA21037@smc.vnet.net>
• Reply-to: Chris Chiasson <chris.chiasson at gmail.com>
• Sender: owner-wri-mathgroup at wolfram.com

```This could be wrong, but I think your simplification only holds if x
is positive and real, not just real. Also, the leaf count of the
expression you want is the same as the leaf count of the expression
you are starting with, so Mathematica probably considers them to be of
the same simplicity. If you really want the expression to look this
way, why not write some code to go find the lowest power of x inside
the polynomial. Divide the terms by that power of x, and multiply the
entire polynomial by that same power, using hold form if necessary.

On Sat, 12 Mar 2005 02:36:58 -0500 (EST), billkavanagh at gmail.com
<billkavanagh at gmail.com> wrote:
> Hi
>
> I'm wondering how to tell mathematica that I want terms like
> Sqrt[x^2+x^4] to be x*Sqrt[1+x^2].   I have an expression with a few
> terms like this in it so manually inserting a
> PowerExpand[Sqrt[Expand[x^2+x^4]] is no good to me.
>
> I've tried a general PowerExpand and Simplify with a Im[x]==0 around
> the whole expression but with no luck.
>
> Does anybody know how to do this?
>
> Thanks,
> Bill
>
> --
> William R. Kavanagh
> http://www.physics.mun.ca/~wkavanag
>
>

--
Chris Chiasson
Kettering University
Mechanical Engineering