Re: Re: simplify expr to 1
- To: mathgroup at smc.vnet.net
- Subject: [mg37959] Re: [mg37953] Re: simplify expr to 1
- From: Andrzej Kozlowski <andrzej at platon.c.u-tokyo.ac.jp>
- Date: Fri, 22 Nov 2002 04:16:08 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
> But some might argue that that isn't true either because > sometimes the result is 1.0 instead of the integer 1. > > In[13]:= > x=2.3; > r=1/2; > x^r*(1/x)^r > > Out[15]= > 1. > > > In[16]:= > x=2; > r=0.5; > x^r*(1/x)^r > > Out[18]= > 1. > > I think this observation is based on a misinterpretation of the way Mathematica treats symbolic expressions. Essentially, if a symbolic expression does not contain floating point numbers then it is treated as exact. Thus: In[1]:= x/x Out[1]= 1 while In[2]:= (1.x)/(1.x) Out[2]= 1. This is consistent with the fact that symbols always have infinite precision. Andrzej Kozlowski Yokohama, Japan http://www.mimuw.edu.pl/~akoz/ http://platon.c.u-tokyo.ac.jp/andrzej/