Learn this math hack to solve this square root in 2 seconds

[anajoanes]

fyi it only works if its consecutive numbers starting from 1 and cubed

[Fred-yqfs]

2 secs... a bit short.
But you should remember that the sum of the cubes is (the sum of the naturals) squared, so the answer is the sum of the naturals = (5+1)*5/2 = 15.

[maxhagenauer]

The reason this works is because the sum of consecutive cubes up to n is the formula [ (n^2) * (n + 1)^2 ] / 4, so taking the square root of this will just make [ n * (n + 1) ] / 2 which is the sum of consecutive integers up to n. Thus, sqrt( 1^3 + 2^3 + 3^3 + ... + n^3 ) = 1 + 2 + 3 + ... + n.

[theultimategamerbro]

I’m confused because if you cube 2 then it’s 8 and the square root of eight isn’t two so how can you add it up like that

[scarletevans]

It would be really useful to mention " n(n+1)/2 " here :-)
For someone who doesn't know about it and won't understand where your solutions comes from, your short is one of the most confusing ways possible to convey that xD

[AmeyKalkotwarr]

This is a series of cubes of n natural numbers.
Formula for Sn :

Sn= [(n)(n+1)]²

4

So 5×6=30
30²=900, √(900/4)=30/2=15

[bhaveshganolia]

You should teach the method and explain it my teacher explain the logic and how this formula work if you don't explain the concepts people will face difficulty in applying the concepts

[SarithaImmadi._._]

15, thankyou very much for the video.

[H_K_beyond]

You can also use the formula 1/6 * n^2 * (n+1)^2

[AntaripHatiboruah]

Teacher: the ans is correct now show me the work
Me: 💀💀

[terrariariley]

Now take the square root of them added together

[orangeoranges-mwsb]

i thought it was only for 1^3+2^3+3^3 and some other ones

[HaydenJory]

14³
(2*7)(14)(14)
(28*98)(14) WRONG
(28*7*14)
2³*7³
27*7
140+49
189*2³
2²*(200+160+18)
2(378)
600+140+16
756


14²+¹
14*14¹/²








16
(4)(4)
(2*2)(4)
8*8
***Only multiply by one multiple★

16
(4)(4)
(2*2)(4)
2*2*4
***Correct

[gothelismyfave]

those are cubed numbers though? so it's the square root of 15*15*15? which isn't fifteen.

[JustinVanTrump]

You're actually incorrect because you are asking for the square root not the cube root and the numbers are cubed not squared

[AquaVerb]

the square root of x^3 doesn't equate to x the square root of x^2 equals x

[farhan]

stupid me thinking its 15 but still have the sq root