Re: Simplify
- To: mathgroup at smc.vnet.net
- Subject: [mg58674] Re: Simplify
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Thu, 14 Jul 2005 02:48:59 -0400 (EDT)
- Organization: The Open University, Milton Keynes, England
- References: <db2g9i$djm$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
paulvonhippel at yahoo wrote:
> I'm having some trouble getting an expression to simplify in an obvious
> way. (There seems to be a long tradition of users posting to this group
> with similar troubles.)
>
> The expression is
>
> poly = p (p - 1) b^2 + s^2
> prod = Sqrt [poly] Sqrt[1/poly]
> Simplify[prod, {0 < p < 1, s > 0, bϵReals}]
>
> which should return one, I think, but doesn't.
>
> I'd be grateful for suggestions.
>
> Thanks!
> Paul
>
Hi Paul,
Use *PowerExpand* rather than *Simplify* since *Simplify* does not
expand powers.
In[1]:=
poly = p*(p - 1)*b^2 + s^2
Out[1]=
b^2*(-1 + p)*p + s^2
In[2]:=
prod = Sqrt[poly]*Sqrt[1/poly]
Out[2]=
Sqrt[1/(b^2*(-1 + p)*p + s^2)]*
Sqrt[b^2*(-1 + p)*p + s^2]
In[3]:=
PowerExpand[prod]
Out[3]=
1
Best regards,
/J.M.