"And now we can just use our calculator"

when you go back to the first level after beating the game:

That's how your brain functions after studying college level maths, can't help getting a little fancy

My one of my classmates did something even funnier. One time it was r^3 = 216. What he did was turn it into r^3-216=0, and then factored using the difference of two cubes formula, and then took like 5 more lines just to find the quadratic part has no real solution.

When you become a software engineer and want to print hello world

The idea is good. I commend your student for that. But if he were to simplify the expression further, he would have to calculate the cubed root of 125 anyways.

Alt title: how real man solve functions

X^3=125 X^(3) = (1+2)5 X=5 P/s: I didn't think I'd get this far...

Khaby then comes in with the cube root and solves it in one step

The roots of the equation are 5, 5ω, 5ω^2 (where ω= (-1±√3i)/2

Continued x=cbrt(e^ln(125)) x=cbrt(125) x=5

when they have access to calculator and dont use cube root

I actually want to cry that I can understand this humor, where as a year ago I was totally scared of mathematics and barely passed it, I'm going to finish my business degree, and get another degree in mathematics, thank you.

smh here's the full proof x= e^(ln(125))/3 Therefore x =e^((ln(125))1/3 x =125^1/3 this is obviously 5 QED

It's funny because I was here thinking "I don't see anything wrong. Isn't this how you are supposed to solve this equation?" Then I looked at the comments, realized the joke and then realized the simplicity of the question.

I love how you cut that video in the end

oh thnx now i can use the calculator ...initially it was hard

"wtf is a cube root" -bprp probably

Lmfao i was literally thinking "hm? what's the problem here?", don't think i would have done it this way, but i didn't realize that it was overcomplicated for some reason

It could also be like Ln x³ = ln 125 3 ln x = ln 5³ 3 ln x = 3 ln 5 Ln x = ln 5 By comparing x = 5 "Life is Simple , we make it difficult "

"smart people don't understand jokes" -sun tzu the art of mathematics

The teacher: Only my method will be followed in the exam The teacher's method

This is the easiest short cut trick I have ever seen in my life for finding cube of a number

From now onwards I will not able to convince myself directly that solution of x³=125 is 5

Me: "5, no need for unnecessary equations)

Meanwhile Cube Root: 🙄

Me in the 8th grade who just cube rooted it and found the answer without calculator- I like your funny word magic man

I love how u made it like 5 times more complicated than it should be.

bro i really just accidentally found the answer by replacing x to 5

Dude, you missed two complex roots.

The audio cut at the end is *immaculate* 💀

Wow, 60seconds of my life that I'll never get back

me: memorized cubes till 10

The most efficient solution

Just remember to use logs only when the exponent is a variable, that usually works for me

This is a very useful beginner introduction to logarithms!

First thought: Yeah, it's 5 and now?

We could also just find the cube root lol

Future Ultron after watching this video : Self-conscious lvl 100

This is exact moment blackpenredpen became student.

wow its an interesting discovery that e to the 3 times logx is just 3rd root of x

This stresses me out to the maxxxx!!! Where did the ln come from?! 😭

I just graduated elementary, but I'm gonna save this video for when I understand what on earth he's saying

When you become a head chef and want to make instant ramen :-

Lmaooo

Wait which step loses complex answers?

dude's making it more complicated than it actually is.

spent forever looking for this video

殺雞偏用牛刀 XD

0:18

I wish I understood this quick trick back in undergrad in the late 2000's when I was taking calculus courses. Still passed but it was literal torture. My math professor wasn't very good at explaining. Basically, the steps when an exponent on a variable is involved is to: - take _ln_ on both sides so exponent can be brought down - isolate the variable - take _e_ on both sides to cancel out the _ln_ on the variable - now just do basic algebra to solve for the variable

Cant we just transpose that cube to other side to give a cube root of 125?

How come we lose the complex solutions by doing this?

Can someone explain why u can move the exponent to the front when there is a ln

Funny how I was just taught natural logarithm 2 hours ago and now this is on my recommendations

I need to really relearn algebra first and then go back into deeper knowledge

Love this format

Cube root of 125 is 5 So 5 cube is 125 Solved

" I've seen this one it's a classic " *avg Asian enters*

Now i know what my dog feels when i talk to him

the way it gets cut off as he says "five" makes this even funnier

I thought this was a without a calculator question 😭😭😭

That cutoff was gold

This is how i am solving my life problems😅

The true asians have already memorized these by heart😂

When you just happened to know that 5^3=125

"WHAT THE F#CK IS A CUBE ROOT 🦅🦅🦅"

High school kid be like - that's 5 ...he starts explaining.... Kid - wtf!!

This method can be transferred to many other problems. That is why he is showing it like that.

I’d love to see this with an example I wasn’t able to pick up on at the same sped at which I know my times tables

The dry comedy was gold

If we want to use the ln() method, here's how: x^3 = 125 ln(x^3) = ln(125) 3ln(x) = ln(5^3) 3ln(x) = 3ln(5) ln(x) = ln(5) e^ln(x) = e^ln(5) x = 5 Or just do it the cool way and cbrt(125)

Ok so let's just turn this into a cubic equation. x^3=125 x^3-125=0 x^3+0x-125=0 This is a cubic equation, so we're gonna apply the Cardano's formula. Since 4*0^3+27(-125)^2>0, therefore: x=cuberoot(-(-125)/2+sqrt((-125)^2/4+0^3/27)+cuberoot(-(-125)/2-sqrt((-125)^2/4+0^3/27))) aAaNd tHiS eQuAls tO fIvE

Guys it’s a joke stop saying he’s doing it wrong just admire the creativity.

Bro escaped the Matrix

When you are getting bored in class

Me who knew the answer was "syntax error" all along

I said "WTF" so audibly at the end

When you are too advanced in math and eventually forgot roots be like:

This is actually the traditional method, before calculators people used log tables for just about everything (although not usually on a perfect cube lol).

When you know it’s 5 right away and feel like a galaxy brain

There are also two more answers using the cubic formula you get 5 and -5/2 ± 5√(3)i/2

Me knowing that it is 5 by looking at it: "Sometimes my genius is almost frightening"

The cube root was just too much lol 😂

Congratulations you made the question much harder than it actually is.

If you consider that ln(125) = 3ln(5) the 3s cancel and the ln cancels with the e to give the answer 5.

You could also simplify 125 to 5^3 and put the three in front of the ln so that you can simply the 3 below. Edit: or you could just avoid using the ln, simplify 125 to 5^3 and put both members under the cubed root so the ^3 goes away.

You can just keep dividing by five too since we know that 125 is a perfect square and 5 is the unit's place.

Cubic Root is crying on the edge of the world

Even switching guns is slower than you switching pens

Lmao when we said and now you can just use your calculator had me dying

why did i feel like this would be more efficient than a cube root for a solid 10 seconds....

Dude's been hitting that Dao Ta Ching with that beard 🤯

The cut was perfection

x³ = 125 ln(x³) = ln(125) = ln (5³) 3ln(x) = 3ln(5) ln(x) = ln(5) e^ln(x) = e^ln(5) x=5 Similarly you could just notice from the start that 125=5³ and since the power on the lhs equals the power on the rhs, the base must be the same so x=5

If we are working with real numbers there's only 1 solutions, but there are 2 More in complex, Let me get all answers. x³=125 ⬜Substract 125 on both sides x³-125=125-125 x³-125=0 ⬜Rewrite 125 as 5³ x³-5³=0 ⬜A difference of cubes a³-b³ can be written as (a-b)(a²+ab+b²) Letting a=x, b=5 x³-5³=0 (x-5)(x²+x•5+5²)=0 (x-5)(x²+5x+25)=0 ⬜If ab=0, a=0 or b=0 x-5=0 or x²+5x+25=0 ◼️Solve for x-5=0 x-5=0 ⬜Add 5 on both sides x-5+5=0+5 x=5 ◼️Solve for x²+5x+25=0 by formula Formula: x=[ -b±√(b²-4ac) ] / 2a Having a=1, b=5, c=25 x²+5x+25=0 x =[ -5+√(5²-4(1)(25)) ] / 2(1) x =[ -5±√(25-4(25)) ] / 2 ⬜Factor 25 x =[ -5±√(25(1-4)) ] / 2 x =[ -5±√(25•(-3)) ] / 2 ⬜Rewrite 25 as 5² and expand the root x =[ -5±√5² • √-3 ] / 2 ⬜ Rewrite -3 as 3•(-1) and expand the root x =[ -5±5√3 • √-1] / 2 ⬜i²=-1 or i=√-1 x =[ -5±5√3 • i] / 2 x =[ -5±5i√3 ] / 2 Therefore x₁ = 5 x₂ = (-5+5i√3) / 2 x₃ = (-5-5i√3) / 2 1 real solution 2 complex solutions, i² = -1

I watched this in slow mo and still couldn't keep up!😂

Solving it as: x^3 - 5^3 = 0 (x-5)(x-5w)(x-5w^2) = 0 Giving x = 5, 5w, 5w^2 the absolute chad way

the guy who invented cube roots :(

Umm.... can't we use the calculator in the first step sir? :')...in this case we don't even have to its 5...