Sum of integers squared explained

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  • Опубліковано 3 лют 2025

КОМЕНТАРІ • 111

  • @tj8870
    @tj8870 9 років тому +155

    This is real mathematics. No memorization, only understanding.

    • @elijahbriar3734
      @elijahbriar3734 3 роки тому

      i guess Im asking the wrong place but does any of you know a method to log back into an instagram account??
      I somehow lost my password. I would appreciate any tips you can give me!

    • @benedicturiah7037
      @benedicturiah7037 3 роки тому

      @Elijah Briar Instablaster ;)

    • @elijahbriar3734
      @elijahbriar3734 3 роки тому

      @Benedict Uriah I really appreciate your reply. I found the site through google and I'm trying it out atm.
      Takes a while so I will get back to you later with my results.

    • @elijahbriar3734
      @elijahbriar3734 3 роки тому

      @Benedict Uriah It worked and I actually got access to my account again. I am so happy!
      Thank you so much, you really help me out!

    • @benedicturiah7037
      @benedicturiah7037 3 роки тому +1

      @Elijah Briar happy to help =)

  • @AmineChM21
    @AmineChM21 9 років тому +53

    THAT WAS BEAUTIFUL

  • @MohaMMaDiN55
    @MohaMMaDiN55 8 років тому +17

    Amazing channel. I really love that !
    I never ever memorize any law or equation unless I don't know where it really came from.

  • @ambassador_in_training
    @ambassador_in_training 2 роки тому +2

    Thank you very much for such wonderfully done videos. It is indeed great to see the pictures and the intuitive ideas behind those great formulas. You do make it much easier to understand them, though I needed to watch the (n+1/2) for the height a few times to realize where it came from ;))))

  • @NatsumiHinata
    @NatsumiHinata 10 років тому +18

    You should do this one next time! (1+2+3+ ... +n)^2 = 1^3 + 2^3 + 3^3 + ... + n^3 = {[n(n+1)]/2}^2

  • @BoZhaoengineering
    @BoZhaoengineering 5 років тому +3

    It is cool!!! This is missing part from my junior and senior middle school. This makes all algebra lively sense and meaningful.

  • @youngkim777
    @youngkim777 7 років тому +4

    I'm just simply amazed... That was a beautiful explanation about the Sum of integers squared. You are awesome. Keep it up! :D

  • @RohitWason
    @RohitWason 4 роки тому

    So concise and so precise. Elegant!

  • @dr.rahulgupta7573
    @dr.rahulgupta7573 4 роки тому +1

    Excellent presentation of the subject. Dr Rahul RohtakIndia.

  • @Reydriel
    @Reydriel 10 років тому +1

    Geometric explanations really are the best way to undestand these things huh :P

  • @isabel7798
    @isabel7798 7 років тому +2

    Wow that was so much better than my textbook! THANK YOU

  • @gamestore7158
    @gamestore7158 3 роки тому +1

    Awesome! the reason why I love mathematics

  • @IaKhanic
    @IaKhanic 10 років тому +1

    Great explanation. i loved the animation :)

  • @vvarr-
    @vvarr- 10 років тому +14

    Awesome explanation! ;) Out of curiosity...what software did you use for the graphics?

  • @ninjamasterpops5931
    @ninjamasterpops5931 2 роки тому

    The visuals really help thank you so so very much I subbed :)

  • @MohaMMaDiN55
    @MohaMMaDiN55 8 років тому +1

    What ! only 17k subscribers ??
    those are all the future doctors I think, good luck.

  • @omar.m.eamiguel
    @omar.m.eamiguel 7 років тому

    That formula is also the formula for counting all visible squares in a square divided by smaller equal squares with n sides. ;-)
    I've also derived that formula when I was high school student after our Mathematics teacher taught us how to derive an equation when x and y values are given! ;-)
    I've come up to derivation of this formula when my brother challenged me to count the number of squares in a 3 x 3 square using matchsticks. Obviously for a young fellow like me, I answered 9 which was wrong because of the fact that there are four 4x4 squares plus the one 3x3 square plus the 9 smallest squares which total is 14 visible squares.
    Because of that, I wondered how to count squares in a big number of side like in chessboard. ;-)

  • @fakherhalim
    @fakherhalim 8 років тому +1

    Very nicely done!

  • @brockobama257
    @brockobama257 8 років тому +2

    wow... beautiful animation i'm subbed

  • @ketofitforlife2917
    @ketofitforlife2917 5 років тому

    1:15 What is the reasoning behind that step? Creating two other copies?

  • @mrlabon123
    @mrlabon123 7 років тому +1

    Thank you. But why do we have to do the steps after 2:36?

  • @mahdinoroozi1614
    @mahdinoroozi1614 3 роки тому +1

    thanks for sharing, what animation software did you use ?

  • @joshuaperling2985
    @joshuaperling2985 4 роки тому

    wow! great video and explanation

  • @geekionizado
    @geekionizado 10 років тому +2

    which software did you use to 3D animate the cubes?

  • @cjcbvbk1447
    @cjcbvbk1447 8 років тому +10

    Math is God's Language! This is awesome! Thank you sir!

  • @facilvenir
    @facilvenir 4 роки тому +2

    There's also an algebraic explanation for this. It's much more difficult to understand but more academic.

    • @drakesmith471
      @drakesmith471 2 роки тому +1

      Do you happen to recall where you came across it? Not saying I’d get it, but a crack at the harder stuff is never a bad thing so long as someone isn’t hard on themselves if they don’t understand it.

    • @facilvenir
      @facilvenir 2 роки тому +1

      @@drakesmith471 I don't remember, but I think there is a video in blackpenredpen explaining it. If not, I'm sure that if you look something like "sum of first n integers" in UA-cam (or google) you'll get the explanation.

    • @drakesmith471
      @drakesmith471 2 роки тому +1

      @@facilvenir it’s funny you mentioned the black pen red pen video, I got it suggested to me but dismissed it thinking it would be geometric by nature and thus repeat of this. Thank you for setting me on the next leg of the journey.

  • @keniangervo8417
    @keniangervo8417 10 років тому

    This was really help ful!!

  • @laurahoughton1289
    @laurahoughton1289 5 років тому +3

    Okay this image of the three stacked squares vaguely puts me in mind of the fact that the derivative of x cubed is 3 (x squared).

    • @lakpasonam721
      @lakpasonam721 4 роки тому

      Your comment was more interesting than the video!
      🙄🤔🤔😮👍👍🙏

  • @profabhishekiitr569
    @profabhishekiitr569 5 місяців тому

    Exceptional

  • @excessreactant9045
    @excessreactant9045 4 роки тому

    Thanks very nice vid

  • @vaibhavpatil2611
    @vaibhavpatil2611 9 років тому

    pls explain integration and differentiation

  • @BrazilMentionedHueHue
    @BrazilMentionedHueHue 8 років тому +1

    thank you

  • @robertcox2263
    @robertcox2263 10 років тому +4

    How long has the equation been around?

  • @blakev.4540
    @blakev.4540 4 роки тому +1

    Why 1/2? Didnt get that part

    • @josevargas-859
      @josevargas-859 4 роки тому

      because the last layer is missing half
      if it were complete it would be one more

  • @shanewolf38
    @shanewolf38 8 років тому +1

    Beautiful! :D

    • @josephma1332
      @josephma1332 4 роки тому

      For the first time I enjoyed mathematics.

  • @wocannaseilai5983
    @wocannaseilai5983 8 років тому +4

    Is everything really solvable with geometry?

    • @vroomie
      @vroomie 8 років тому

      Wocannasei Lai possibly not.

    • @vroomie
      @vroomie 8 років тому

      Wocannasei Lai possibly not.

    • @Xphy
      @Xphy 7 років тому +1

      it's a good question ;)

  • @thabsor
    @thabsor 4 роки тому

    thank you man

  • @endlessduck1642
    @endlessduck1642 7 років тому

    i love this one

  • @نیما-ه2ب
    @نیما-ه2ب 7 років тому

    very thanx for video!

  • @SledgerFromTDS.
    @SledgerFromTDS. 4 роки тому +1

    Nice

  • @BinduVK-f5h
    @BinduVK-f5h Рік тому

    Thnkss

  • @markcasiano6501
    @markcasiano6501 3 роки тому

    starting at 2:37 is wrong

  • @tofolcano9639
    @tofolcano9639 8 років тому

    how could
    n(n+1)(n+1/2)=
    =[n(n+1)(2n+1)]÷2?
    shouldn't it be [2n(2n+2)(2n+1)]÷2?
    so it could cancel out on all of the ecuation?

  • @farahjaber6024
    @farahjaber6024 8 років тому +1

    (10*11*21)/6=(2310)/6=385 clever !
    I checked this on my calculator !

  • @omar.m.eamiguel
    @omar.m.eamiguel 4 роки тому

    Hi. I'm just wondering if 1² + 2² + 3²... +24² = 4900, and the square root of 4900 is 70, is it possible to perfectly arrange all the 1x1, 2x2, 3x3 up to 24x24 squares inside the big square of 70x70 without space or overlapping areas?

    • @AmanSingh-or6yf
      @AmanSingh-or6yf 4 роки тому

      But sir we need cubes intsread of squares.

    • @samuraijosh1595
      @samuraijosh1595 4 роки тому

      @@AmanSingh-or6yf No..? He wants to arrange squares inside a big square. Not sure whether things won't overlap but you don't need cubes...

  • @vaibhavpatil2611
    @vaibhavpatil2611 9 років тому

    how to derive this formula algebraically ?(i mean without the help of geometry?)

    • @lucasm4299
      @lucasm4299 9 років тому

      Khan Academy has an explanation. It required system of equations.
      Something like that.

    • @lucasm4299
      @lucasm4299 9 років тому +1

      +Daniel Vieiralves
      Interesting....

    • @lucasm4299
      @lucasm4299 9 років тому +1

      +Daniel Vieiralves
      Though, I would't be able to comprehend it.
      Speaking about the sum of powers....
      x + (x+1) + (x+2)...
      x^2 + (x+1)^2...
      Was this the intuition for Bernoulli numbers?
      I'm very interested in them because they appear in the expansions of trig functions, such as tan(x).
      All I know is that there is a first and second set of Bernoulli numbers which differ from just one number.

    • @lucasm4299
      @lucasm4299 9 років тому

      +Daniel Vieiralves
      Eu não posso entender a tua língua matemática e estratégia.
      É muito complexa quando pode ser mais fácil.
      I still prefer Sal's method. Easier to see the derivation.
      When you figure about Bernoulli's numbers please tell me.
      Obrigado de novo.

    • @lucasm4299
      @lucasm4299 9 років тому

      +Daniel Vieiralves
      +Daniel Vieiralves
      P.s.
      Your English is PERFECT.
      The only thing was the "wasn't".
      *Which part weren't you able to grasp.
      :)

  • @vaibhavpatil2611
    @vaibhavpatil2611 9 років тому +1

    didn't know the formula but amusing

  • @chounoki
    @chounoki 9 років тому +6

    You can use 6 copies to make a perfect cube of n x (n+1) x (2n+1), which would be much better than this 1/2 "half height" proof.

    • @chrismccarthy6033
      @chrismccarthy6033 9 років тому +1

      Chounoki It will not be a cube, but a rectangular prism

    • @patrickwienhoft7987
      @patrickwienhoft7987 9 років тому +2

      +Chounoki you could also slice the green thing at the top in half and (vertically) and put the cut off half on the red area

  • @aschetos
    @aschetos 4 місяці тому

    👏👏👏

  • @paimfp
    @paimfp 7 років тому

    Could you accept the subtitles for Brazil please ?

  • @katerynakonotopska2941
    @katerynakonotopska2941 10 років тому

    wow amazing :)

  • @misteratoz
    @misteratoz 8 років тому

    I was able to reason out the sum of natural numbers to n on my own. I was trying to do similar with this one but I couldn't visualize how to make a predictable solid out of the pyramid. I especially couldn't visualize how those pyramids would stack together. But this is really great. Is there a general way to prove these formulas?

    • @SO3rl
      @SO3rl 7 років тому

      misteratoz Yes, but the one I've seen uses algebra. I tried deriving the case for cubes with geometry and I got pretty close, but it's substantially harder than this one, and I found a much easier way without geometry.

  • @Arsbars1
    @Arsbars1 8 років тому

    AMAZING)

  • @xelxlolox
    @xelxlolox 9 років тому

    make one with 1^3+2^3 etc..

    • @branthebrave
      @branthebrave 8 років тому

      It's possible I assume, but harder to put the pieces together.

    • @branthebrave
      @branthebrave 8 років тому +3

      Actually, it's really hard because you need to do this in the 4th dimension, you can't make flat surfaces with cubes, only more cubes... Like 3^3=27, but 27 can't make a square, only a cube (a 3x3 cube). But maybe there is a way in the third dimension.

  • @prateekmourya9567
    @prateekmourya9567 4 роки тому

    Much better than #3blue1brown

  • @joshliu4428
    @joshliu4428 8 років тому +1

    Just use induction.

    • @qbwkp
      @qbwkp 8 років тому

      +Josh Liu pls tell me how this is done.

    • @Pokiwar
      @Pokiwar 8 років тому +1

      Tyrone Lannister sorry for bringing you back to this video after so long, but I just found it and hope to explain it if you haven't already learnt yourself
      Proof by induction is not how you get the formula, it's a way to prove it right for all values of n in a completely algebraic not geometric way.
      first, your prove it true for n=1. Then, make the assumption it is true for n=k, and you get k(k+1)(2k+1)/6 and then you find the arithmetic progression expansion (1+4+9+16...+k^2). then you find the expansion for n=k+1, in this case is (k+1)(k+2)(2k+3)/6 then, you also find the arithmetic progression expansion (1+4+9+16...+k^2+(k+1)^2) and you equate it to the expansion for k. you should see that this expansion is simply the same as the expansion for k + (k+1)^2. thus you can equate the two right hand sides and see if they are equal. From this you get k(k+1)(2k+2)/6+k^2=(k+1)(k+2)(2k+3)/6. if your algebra is correct then these should be equal. Thus, you've proved a ink between subsequent integers. Plugging in k=1, you can show that as this is true from the first part, then it must be true to the subsequent integers 2, and if true for 2, it is true for 3 and so on and hence your proved it is true for all positive integers. This is proof by induction.

    • @akcurtain8936
      @akcurtain8936 7 років тому

      Induction doesn't help with understanding. It only helps with proofs.

  • @luiginodilenardo6820
    @luiginodilenardo6820 2 роки тому

    Guarda mio video
    Geometria numerata
    Superficie area cerchio

  • @muhammadsheyhidan5010
    @muhammadsheyhidan5010 6 років тому +1

    I cannot understand that half height thing. That's it 😣

  • @caiobrainer1
    @caiobrainer1 4 роки тому

    Damn

  • @mal1k_me
    @mal1k_me 3 роки тому

    Even though the video is about squared integers, the visual explanation works with cubes ... Isn't it supposed to be explained with squares? But it wouldn't work!

    • @tyishak8564
      @tyishak8564 3 роки тому

      This explanation is saying 1 is represented by one cube, 2 squared is being represented by 4 cubes, 3 squared is being represented by 8 cubes so each individual cube is just being represented as one so the aim is to find out the total number of cubes so we can get 1+4+9+16…+n.

  • @drsuper8180
    @drsuper8180 4 роки тому

    Very nice but with 6 of these pyramids no algebra was necessary!

  • @adityaln9361
    @adityaln9361 3 роки тому

    if you take it as squares, you get n(n+1)/2 when you do that, for n(n+1)/2 to be= n(n+1)(2n+1)/6 , n has to be 1 , so either your wrong or im missing something , either way this is bad video

  • @Rócherz
    @Rócherz 3 роки тому

    To calculate the sum of the first _n_ *squares,* let us talk about *cubes,* first…

  • @FlightPolice
    @FlightPolice 7 років тому +1

    Sorcery

  • @quanhoang3550
    @quanhoang3550 Рік тому

    Nước ngoài ngta học bản chất ở vn chơi học thuộc, mẹo :))

  • @jakobee5667
    @jakobee5667 9 років тому

    what the hell math is crazy

  • @wooper4322
    @wooper4322 6 років тому

    I CAN’T UNDERSTAND!!! AM I DUMB????