Solving x^3=8

[theprimegames]

Pov: you have 100k+ hours in a game and you decide to play it again

[IamNotLC]

Cube roots were invented in 499CE

People before 499CE :

[okaro]

This is easy to those who know the three phase alternating current. Raising to the third triples the angle to the positive X-axis so the angles are 0/3, 360°/3 and 720°/3.

[andytraiger]

Damn. I didn't think of imaginary solutions...

[myfishcalledbobble]

simpler version
x³ = 8
2³ = 8
x = 2

[Meanthes]

He did quadratic formula without actually doing it 😯

[youtubercocuq]

The polar form would be easier:

x = r * e^jt
x^3 = r^3 * e^3jt = 2^3 = 2^3 * e^0

=> r = 2 and 3t = 0 + 2pi*k
=> t = 2pi/3 * k

=> t = 0, 2pi/3, -2pi/3

=> x = 2, 2*e^j2pi/3, 2*e^-j2pi

[shashankmuralidharan]

Wouldn't the second qnser not give you 8 if plugged in?

[homayounshirazi]

limitless numbers, limitless solutions! limited intelligence, limited discoveries. 1000 years ago we discovered how to solve second degree equations, we are now defining sq root of negative numbers. if humanity could survive, who knows what we would discover in the next few decades.

[Burntheadversary]

Where are you getting the +1 from when you add it to -4

[snatcc]

I ALWAYS want to put the I *behind* (for some reason?!!)

[Aarpod]

Do the hardest one you can possibly find. Make a whole video of you tryina solve it

[Anm]

I know for the second answer you can solve that by plugging it in the quadratic formula. I don't understand the method used here, like where that +1 come from.

[aaa-jzki]

He could have just done like cube root of 8 is 2







Sorry if anyone else had commented on this before me but like I felt he is overcomplicating it

[ianshaw]

Why are you overcomplicating it? Take the cube root of both sides...x=2!!!

[bajiepbihka]

Привет из России, мне всегда было интересно что означает символ "i" в математике поскольку мы такое не изучали

[macromachina]

? strange i would say you had it up until 4th i would say just div squ 8/8/8 soooo like 8/8 = 1 right then 1/8 = 0.125... i dfk

[mircoceccarelli]

x^2n = m, m < 0

m = - k = k i^2, k > 0

i^2 = - 1 .

👍👍👍

[jon]

Not me, saying “bro please just take the cube root”

[EA-ignd]

then you could have simply written (blablabla) instead of (x²+2x+4).😂