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.