Proof by Induction : Sum of series ∑r² | ExamSolutions

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  • čas přidán 25. 03. 2012
  • Here you are shown how to prove by mathematical induction the sum of the series for r squared. ∑r²
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Komentáře • 53

  • @Sarank1107
    @Sarank1107 Před rokem +18

    10 years later and this goat is still carrying further maths

  • @justinemacarat6992
    @justinemacarat6992 Před 9 lety +7

    thats a very straight line.

  • @BillStrait
    @BillStrait Před 11 lety +1

    I'm taking a discrete math course online. This exact problem is on this week's assignment. For the first time since the course began, I feel I understand what's happening. Thanks a lot.

  • @thomaslee7507
    @thomaslee7507 Před 9 lety +28

    You sir are a genius! This video is flawless and helped me grasp the concept in one go! Thanks a lot!

  • @iamkaja0
    @iamkaja0 Před 12 lety +4

    OH MY GOD THANK YOU. Exam tomorrow - why didn't I discover this earlier!? Better late than never though, thank you so much!

  • @cooldude22032
    @cooldude22032 Před 8 lety +9

    Thank you, you did a much better explanation than my teacher who thought it would be a good idea to rush through the last chapter of FP1

    • @jamescopland2649
      @jamescopland2649 Před 8 lety +1

      +Matthew Lunn Same here bro we took ages on matrices and complex numbers so ended up rushing the last two chapters; and the exam is tomorrow :(

    • @nagul3165
      @nagul3165 Před 7 měsíci

      7 years later, and my exam is 2 days away, I hope y'all are having a good life ✌✌@@jamescopland2649

  • @AaaAaa-yb2nb
    @AaaAaa-yb2nb Před 7 měsíci

    A huge help. Thanks for the clear explanation. FINALLY understand each step.

  • @julesofharbledown9591
    @julesofharbledown9591 Před 2 lety +1

    Immensely helpful, thank you. I was missing a step the textbook just didn't explain well.

  • @rosin40
    @rosin40 Před 9 lety

    Great explanation! This was really easy to follow and understand.

  • @dhvsheabdh
    @dhvsheabdh Před 11 lety +3

    I assume you're wondering how the hell he's changed the "(k+1)^2" into 6(k+1)?
    Well: Already, from the equation we can see that there are essentialy two things being added together. We have the Sum from r=1 to k of r^2, equal to k/6(k+1)(2k+1) and (k+1)^2. The thing is, we want to add both of these things toegther. If I make it more simple, it's like trying to add a/6 and b in one bracket without any fractions. It is neccessary to know that b is equal to 6b/6. So (see next comment...)

  • @Soojene
    @Soojene Před 9 lety

    The exam solutions guy is an absolute lad!

  • @nissimzezewa9285
    @nissimzezewa9285 Před rokem

    Thank you
    Now i really understand the topic

  • @aberedenisiokou2929
    @aberedenisiokou2929 Před rokem

    Great one sir

  • @pragyakansal9017
    @pragyakansal9017 Před 2 lety

    this helped so much!!

  • @ese7560
    @ese7560 Před 2 lety

    Thank you
    This helps alot🥰

  • @GabbersLJ
    @GabbersLJ Před 8 lety +1

    Oh my word that was so helpful thank man I was lost as he'll and you have shown me the light, thx so much.

  • @dhvsheabdh
    @dhvsheabdh Před 11 lety

    Can you do more of these Proof by Mathematical induction videos?

  • @user-ud9tr8gg9i
    @user-ud9tr8gg9i Před 3 měsíci

    Teaching and learning here is good

  • @linping6905
    @linping6905 Před 3 lety

    Thank you I appreciate thos

  • @dhvsheabdh
    @dhvsheabdh Před 11 lety

    well, the lone k dissappearance is simple. In the equation you can see that (1/6)k(k+1)(2k+1). They are all to be multiplied together, so it makes no difference in which order they are. So abcd = dabc = dcba etc. So he's moved the k infront of the (2k+1), so it makes it seem more simple as he multiplies everything by (1/6)(k+1). So, as (1/6)(k+1) is a factor of (1/6)(k+1)k(2k+1) and (1/6)[6(k+1)^2)], they can be added together, and hence simplified. Message me if you have any problems :)

  • @liamchandler8860
    @liamchandler8860 Před 8 lety +4

    Very clear, thank you

  • @firstname4337
    @firstname4337 Před 2 lety

    this was helpful

  • @thabanindlovu7367
    @thabanindlovu7367 Před 6 lety

    I really appreciate your teaching Sir, l'm a step ahead. Thank you.

  • @dhvsheabdh
    @dhvsheabdh Před 11 lety

    So...(k+1)^2 is equal to 6 lots of this, divided by 6. But BECAUSE it has been divided by 6, just like the (1/6)n(n+1)(2n+1), they can now be added together for simplification. However, another common factor in both of these terms to be added is (k+1), so he's decided to take that out also. So if you take out a sixth and (k+1) out of both of the things to be added, you end up with (1/6)(k+1) as the thing outside of the brackets. However, you're probably also wondering where the lone k has gone..

  • @MEETPANCHOLI07
    @MEETPANCHOLI07 Před 7 lety

    hey.....what about 7+10+13+16+....+(3n+4)=n/2(3n+11).....what would the k+1 be?

  • @leoniduvarov6565
    @leoniduvarov6565 Před 7 lety +2

    This seems to be a very hard concept for people to explain. I applaud you for doing a great job at explaining it clearly

  • @kevinklose
    @kevinklose Před 11 lety

    you are awesome

  • @nuse420
    @nuse420 Před 7 lety +1

    I do not see where you get 1/6th from both sides the addition sign.

  • @cary_domiii
    @cary_domiii Před 4 lety

    I've been struggling with this problem to find our that my only mistake was that I forgot to square (k+1)....

  • @morganabbotts
    @morganabbotts Před 10 lety

    How would I prove sigma r^3?

  • @ExamSolutions_Maths
    @ExamSolutions_Maths  Před 12 lety

    I would have thought so.

  • @ExamSolutions_Maths
    @ExamSolutions_Maths  Před 12 lety

    Good luck

  • @lavarball61
    @lavarball61 Před 8 lety +1

    great video. but this induction stuff is soooooo longggg

  • @ExamSolutions_Maths
    @ExamSolutions_Maths  Před 11 lety

    Cool

  • @mrboyban
    @mrboyban Před 4 lety +5

    If you hate proof by induction put your thumbs up

  • @oOQubixOo
    @oOQubixOo Před 12 lety

    is this s1?

  • @persiangulfcat
    @persiangulfcat Před 9 lety

    ありがとう!

  • @BorisMediaProds
    @BorisMediaProds Před 6 lety

    You kind of sound like Raoul Silva from skyfall.

  • @mohashifa6286
    @mohashifa6286 Před rokem

    Likely

  • @ExamSolutions_Maths
    @ExamSolutions_Maths  Před 12 lety

    No, FP1

  • @jared6893
    @jared6893 Před 6 lety +1

    I don get iyt

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    @ExamSolutions_Maths  Před 10 lety

    Check out my website. It is on there.

  • @elitegamer95
    @elitegamer95 Před 11 lety

    Story Bro

  • @andrewe9527
    @andrewe9527 Před 7 měsíci

    okay callux

  • @sheshanfernando-uv1uj
    @sheshanfernando-uv1uj Před 5 měsíci

    Pulling out 1/6 was not right

  • @faithelias2798
    @faithelias2798 Před 2 lety

    God loves you and he wants to save everyone, but in order for him to do that, you need to repent and be baptized. Also share his gospel with everyone you come in to contact with and keep his commandments 🙏🏾😘