The example in the text is not the Klein four group. All elements of the Klein four group (except the identity) have order 2. But *i* in the example has order 4. Beetbeet 14:27, 11 June 2007 (EDT)

- Thank you. Please make your correction yourself. That's what this software is for. Godspeed.--Aschlafly 14:38, 11 June 2007 (EDT)
- Ok, I made the correction. Beetbeet 15:56, 11 June 2007 (EDT)

IMO, it's important to give the most basic examples, first. What's about a group of matrices as an example of a non-abelian groub? Or would be better? DiEb 11:06, 2 August 2008 (EDT)

It doesn't make sense to speak of a positive root of x^2 + 1 = 0... --BRichtigen 12:05, 17 November 2008 (EST)

- You can't just say "the" square root of -1; there are two. The positive square root is +i, as opposed to -i. -CSGuy 12:22, 17 November 2008 (EST)

- Of course, there are two. You choose
*a*root of x^2 +1 = 0.But what does make the one positive, the other negative? Only because you named one*i*- arbitrarily, the other becomes its negative :-) - --BRichtigen 14:04, 17 November 2008 (EST)

- Of course, there are two. You choose