Re: (-1)^(1/2.) on Mathematica!
- To: mathgroup at smc.vnet.net
- Subject: [mg107523] Re: (-1)^(1/2.) on Mathematica!
- From: Szabolcs Horvát <szhorvat at gmail.com>
- Date: Tue, 16 Feb 2010 03:50:50 -0500 (EST)
- References: <hlb8qi$rm5$1@smc.vnet.net>
On 2010.02.15. 11:48, Legendre wrote: > Hi, > > I tried the expression (-1)^(1/2.) on Mathematica 7.0, I got 6.12323*10^(-17) + 1. i. By using //N there is no problem. But using 2. it gives a wrong answer. > The answer is not wrong, it is just inexact due to roundoff errors. Machine precision numbers (which are used by default) have ~15 significant digits, so 6*10^-17 is negligible compared to 1 I. Use Chop[] to get rid of it.