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From: "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com>
Newsgroups: sci.math
Subject: =?UTF-8?B?UmU6IHjCsis0eCs1PTA=?=
Date: Wed, 22 Jan 2025 14:57:28 -0800
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On 1/22/2025 2:42 PM, Moebius wrote:
> Am 22.01.2025 um 23:16 schrieb Chris M. Thomasson:
>> On 1/22/2025 5:48 AM, Richard Hachel wrote:
> 
>>> x² + 4x + 5 = 0
>>>
>>> This equation has no root, and <bla>
> 
> It has the two "roots" (solutions):
> 
> x = -2 - i
> x = -2 + i
> 
> Hint:
> 
> x² + 4x + 5 = (x + 2)² + 1.
> 
> Hence x² + 4x + 5 = 0 is equivalent with (x + 2)² + 1 = 0 or (x + 2)² = 
> -1. So x + 2 has to be a (one or more) complex number(s) z such that z² 
> = -1. We know such numbers, they are i and -i (and there aren't more). 
> Hence we have x + 2 = i or x + 2 = -i resp. And hence x = -2 + i or x = 
> -2 - i resp.
> 
>> The x^2 component has two roots.
> 
> Doesn't make much sense. :-P

Shit happens. When I see x^2 and think of complex numbers, I think of 
two roots. This can imply that there are two solutions.