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
>
>