Why is sqrt(x²) not equal to x?

[Rama214]

Seriously, what the hell? :wth:

[profan]

[QUOTE=koekje4life V2;24518916]Why are you people making his maths homework for him?[/QUOTE]

So something you can't answer is homework

[PacificV2]

[QUOTE=koekje4life V2;24518916]Why are you people making his maths homework for him?[/QUOTE]

This isn't exactly a "SOLVE MY INTEGRAL" question or someone asking what's the square root of nine.

Plus this isn't the kind of homework you ask FP help with - mostly everyone here is 16 and under.

[editline]06:28PM[/editline]

[QUOTE=Profanwolf;24518994]So something you can't answer is homework[/QUOTE]

Sounds about right for me!

[Number-41]

I'm preparing my math for college, it's not homework, it's just practice and no teacher is involved.

Also, I checked a math book and the rule a^bc=a^cb is only valid for strictly positive real numbers. It doesn't say anything about other cases...

The math course where I stumbled upon this problem says this:

[img]http://gyazo.com/fc65db694c3f1e15c99baefe98422005.png[/img]

[B]For x larger than 0, sqrt(x²)=x, but for x smaller than 0: sqrt(x²)=-x
E.g: x=-1 then sqrt((-2)²)=sqrt(4)=2=-x

But there are numerous sites stating that sqrt((x)²) is absolute value...[/B]

Also I am surprised that even JohnnyMo1 even can't find a direct solution, perhaps it's not such an easy answer :D

Also, application of this rule with limits:

[img]http://gyazo.com/0bb3993c2afe49c3d05a2c76647f1c83.png[/img]
("met" translates to "with", "voor" to "for")

[B]Edit:[/B]

I think I'm gonna join the xkcd forums...

[PacificV2]

[QUOTE=Number-41;24519837]I'm preparing my math for college, it's not homework, it's just practice and no teacher is involved.

Also, I checked a math book and the rule a^bc=a^cb is only valid for strictly positive real numbers. It doesn't say anything about other cases...

The math course where I stumbled upon this problem says this:

fuck you images trig

[B]For x larger than 0, sqrt(x²)=x, but for x smaller than 0: sqrt(x²)=-x
E.g: x=-1 then sqrt((-2)²)=sqrt(4)=2=-x

But there are numerous sites stating that sqrt((x)²) is absolute value...[/B]

Also I am surprised that even JohnnyMo1 even can't find a direct solution, perhaps it's not such an easy answer :D

Also, application of this rule with limits:

more imagers
("met" translates to "with", "voor" to "for")

[B]Edit:[/B]

I think I'm gonna join the xkcd forums...[/QUOTE]
Oh, that's simple then.
Remember how the "absolute value" function is defined.
[img]http://dl.dropbox.com/u/5359941/gif.latex.gif[/img]
Now rendered in LaTeX for your viewing pleasure
So there!

[Number-41]

There we have it, I learned this rule in the first chapter! I knew it was something simple...