Re: Square root of a square
- To: mathgroup at smc.vnet.net
- Subject: [mg107845] Re: Square root of a square
- From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
- Date: Sun, 28 Feb 2010 04:54:28 -0500 (EST)
- References: <201002270813.DAA11868@smc.vnet.net>
On 27 Feb 2010, at 09:13, Mariano Su=E1rez-Alvarez wrote:
> Hi all,
>
> Mathematica evaluates FullSimplify[Sqrt[x^2]] to Sqrt[x^2], while it
> tells me that FullSimplify[Sqrt[x^2] == x] is True.
> Are these the expected answers?
>
> -- m
>
The second certainly not the answer I would expect, in fact this looks
to me like a serious (perhaps even "shocking") bug. It certainly
contradicts this answer:
FindInstance[Sqrt[x^2] != x, x]
{{x -> -(109/5) + (11*I)/5}}
Andrzej Kozlowski
- References:
- Square root of a square
- From: Mariano Suárez-Alvarez <mariano.suarezalvarez@gmail.com>
- Square root of a square