[ 3 / biz / cgl / ck / diy / fa / ic / jp / lit / sci / vr / vt ] [ index / top / reports ] [ become a patron ] [ status ]
2023-11: Warosu is now out of extended maintenance.

/sci/ - Science & Math

View post   
File: 6 KB, 169x326, whjat.png [View same] [iqdb] [saucenao] [google]
6853765 No.6853765 [Reply] [Original]

Why isn't this -2?

(-2) * (-2) * (-2) = -8

>> No.6853773

>>6853765
Why only choose one answer when there's actually 3?

>> No.6853779

>>6853773
There is only one answer...

don't be vague

>> No.6853782

>>6853779
There is only one answer that is at its simplest form yes. but 12/4 = 3. and both are correct.

>> No.6853785

>>6853779
<div class="math">-2, -2e^{2\pi \frac{i}{3}}, -2e^{4\pi \frac{i}{3}}</div>

>> No.6853786

>>6853782
can you stop shitposting

>> No.6853792

>>6853785
that doesn't answer my question.

why doesn't wolfram alpha show that the answer is -2

>> No.6853797

>>6853792
Because it wants you to be aware that it's 3 solutions and not 1?

I don't know ask the retards who made it.

>> No.6853802
File: 13 KB, 560x365, what.png [View same] [iqdb] [saucenao] [google]
6853802

>>6853797
?

>> No.6853803

>>6853765
>What are roots of unity? And other thoughts from highschool.

>> No.6853805

>>6853803
IDK what's a root of unity.

>> No.6853810
File: 328 KB, 497x658, 1413663526280.png [View same] [iqdb] [saucenao] [google]
6853810

>>6853805

>> No.6853816

>>6853805
www.google.com

>> No.6853821

>>6853802
What's the question mark for? That calculator gives you the principal cube root.

>> No.6853824

>>6853821
Shut the fuck up, kid

>> No.6853830

>>6853824
Did my disambiguation distress you?

Sorry for bringing clarity into a situation where you clearly want none.

>> No.6853834

>>6853830
did my alphaness distress you?

sorry for bringing my dick into your mum's cunt

>> No.6853841

>>6853765
It's probably a hint to the fact that the cube root of -1 has different values as this >>6853785 says. In terms of real numbers, -2 is the only answer (for an angle from -Pi to Pi) but there are other complex numbers (in the same range) that solve the problem.

>> No.6853845
File: 2 KB, 99x125, 1399578282049s.jpg [View same] [iqdb] [saucenao] [google]
6853845

>>6853834

>> No.6853851

You see where it says "Assuming the principal root"? Look up what that means.

>> No.6853855

>>6853765
Wolfram takes the principle root to be the complex root of least angle. -2 has angle pi in the complex plane, while 2*e^(ipi/3) has angle pi/3 so it is chosen as the principal root.

>> No.6853865

>>6853851
Kiss my ass, nerd

>> No.6854185

>>6853765
There are three solutions to the equation -8 = z^3 but we want functions to only take one value so we have to choose a "branch" for the cube root function. If you look closer, it says "assuming the principal root" which is a special branch.

>> No.6854398

>>6853773
>Why only choose one answer
>what is a function and why does the radical operator represent one

>> No.6854399

>>6854185
+1 good explained