Re: Why can't Mathematica tell when something is algebraically zero?
- To: mathgroup at smc.vnet.net
- Subject: [mg108170] Re: Why can't Mathematica tell when something is algebraically zero?
- From: sashap <pavlyk at gmail.com>
- Date: Tue, 9 Mar 2010 06:27:24 -0500 (EST)
- References: <hn2ltj$3kt$1@smc.vnet.net>
On Mar 8, 5:09 am, mmdanziger <mmdanzi... at gmail.com> wrote:
> This isn't the first time that I've encountered something like this in
> Mathematica but in my calculations I got a term like this:
>
> r^2 Sqrt[(r^3 + r + 2)/r] - Sqrt[r^3 (r^3 + r + 2)]
>
> Which is obviously identically zero.
In[73]:= FindInstance[
r^2 Sqrt[(r^3 + r + 2)/r] != Sqrt[r^3 (r^3 + r + 2)], r, 2]
Out[73]= {{r -> -37 + (108 I)/5}, {r -> 51/5 - (228 I)/5}}