Re: problem of evaluating SQRT
- To: mathgroup at smc.vnet.net
- Subject: [mg28022] Re: problem of evaluating SQRT
- From: "Nicholas Konidaris" <npk at jpl.nasa.gov>
- Date: Wed, 28 Mar 2001 02:40:54 -0500 (EST)
- Organization: Jet Propulsion Laboratory - Pasadena CA
- References: <99pd51$leb@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Dear Pek: You must use the function PowerExpand, which, as you can guess, does a series expansion of x^(1/2): Example: PowerExpand[Sqrt[x^2]] Good luck, n "Pek" <phsoh at alum.mit.edu> wrote in message news:99pd51$leb at smc.vnet.net... > Hi, > > We have a question of how sqrt can be evaluated. > > In[1]:= > Sqrt[x^2] > > Out[1]= > (This part is just sqrt[X^2]) > > Below we expect the result to be zero but it isn't. How can we get the > correct answer in this case? > > In[2]:= > Sqrt[x^2] - x > > Out[2]= > (This part is -x + sqrt[x^2] ) > > Will really appreciate your help. Thanks. > > Pek > >