Divisibility Proof (2 of 2: Using algebraic expansion)

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  • เผยแพร่เมื่อ 19 ม.ค. 2025

ความคิดเห็น • 36

  • @andrearredondo
    @andrearredondo 3 ปีที่แล้ว +18

    Recently, Eddie visited our school. On behalf of our school we would love to say thank you for your visit and time.

    • @criped3251
      @criped3251 3 ปีที่แล้ว +1

      Yoo its andre

    • @TheWasian
      @TheWasian 3 ปีที่แล้ว +1

      Okay Andre A

  • @conamore7887
    @conamore7887 3 ปีที่แล้ว

    I've learned a lot from watching your free TH-cam videos. I wonder why people have been brain washed into believing that valuable things are always not for free. I'm among the lucky ones in Uganda who have access to this quintessential mathematics teacher . Te doy las gracias por todos, Eddie woo .

  • @davidplanet3919
    @davidplanet3919 3 ปีที่แล้ว +2

    The last expression is classic binary addition. For n = 4 for example, 2^4 = (2^3 + 2^2 + 2^1 + 1) + 1. Or in binary 10000 = 1111 + 1.

  • @lutfaralif5880
    @lutfaralif5880 3 ปีที่แล้ว +1

    My favourite..an absolute best at explaining and making things fun💜

  • @arimermelstein9167
    @arimermelstein9167 3 ปีที่แล้ว +1

    I have a small nitpick. I assume that you mean that if a^(n-1) is prime for all n, then a=2. Because, for example, if a=8, a^1-1 = 7 which is prime. This is because the second part is 1.

  • @omerayhan7751
    @omerayhan7751 3 ปีที่แล้ว +1

    thank you for enlightening us professor

  • @kentonjones5394
    @kentonjones5394 3 ปีที่แล้ว +1

    In (ii), can n = 1 be another solution

  • @sundarasubramanian9058
    @sundarasubramanian9058 3 ปีที่แล้ว +1

    Sir could u say what r the equipments u r using for maths online class sir...

    • @BillyShears230
      @BillyShears230 3 ปีที่แล้ว +1

      He is using an iPad Pro with an Apple Pencil, and the app he is writing on is notability,not sure if that answers your question

  • @aashsyed1277
    @aashsyed1277 3 ปีที่แล้ว

    8:18 not really true what if the other part is not prime..............

  • @zilvarro5766
    @zilvarro5766 3 ปีที่แล้ว

    You should probably mention that n>1 in (ii)

  • @santiagopabstmeschini5033
    @santiagopabstmeschini5033 3 ปีที่แล้ว +3

    But 3^1 -1 is not equal to 2^(some integer) - 1.
    So It doesn't have to be a = 2

    • @Cyrathil
      @Cyrathil 3 ปีที่แล้ว +1

      My immediate thought was a = 8 (8^1 - 1 = 7 is prime, but a != 2) but similar.
      Maybe I'm missing something, but I don't really understand the hand-waiving of the right product never being equal to 1. If n = 1, the right-side is always equal to 1, so the left product can be basically anything.

    • @erik_forsmoo
      @erik_forsmoo 3 ปีที่แล้ว

      For n=1 the equation becomes a^1 - 1 = (a - 1) * 1, or a - 1 = a - 1. So at that point we're just stating that if a-1 is prime, then a-1 is prime, which is redundant. It would probably be best to just exclude n=1 from the equation.

    • @jamiewalker329
      @jamiewalker329 3 ปีที่แล้ว

      Eddie doesn't do special cases.

    • @jesusalycastrobernal7386
      @jesusalycastrobernal7386 3 ปีที่แล้ว

      It has to be a=2 for all primes that are of the form a^n-1, the case for a=3 is the exception but only works for n=1, despite the case for a=3, there is no other integer a distinct of 2 that satisfies a^n-1 is prime.

    • @jesusalycastrobernal7386
      @jesusalycastrobernal7386 3 ปีที่แล้ว

      @@Cyrathil in that case, 8=2^3 so a=2 and n=3, is like saying that 32^1-1=31 is prime, but 32=2^5

  • @SeeTv.
    @SeeTv. 3 ปีที่แล้ว

    Really cool coincidence how Flammable Maths and you made a video about it over the span of a few days.

    • @aashsyed1277
      @aashsyed1277 3 ปีที่แล้ว

      what video?????

    • @SeeTv.
      @SeeTv. 3 ปีที่แล้ว

      @@aashsyed1277 the newest one I think

  • @jamiewalker329
    @jamiewalker329 3 ปีที่แล้ว

    (x^n -1)/(x-1) is the sum to n terms of a geometric series first term 1 and common ratio x. Done.

  • @lumist9671
    @lumist9671 3 ปีที่แล้ว +4

    Really like your teaching and your class!! Hope I can get some insights from you in terms of my channel if possible, haha (:

  • @Ashu-bv3ej
    @Ashu-bv3ej 3 ปีที่แล้ว

    What is your IQ sir

  • @nova4452
    @nova4452 3 ปีที่แล้ว +1

    Love the signature on my arm thank you

    • @criped3251
      @criped3251 3 ปีที่แล้ว +1

      Hello Josh

    • @nova4452
      @nova4452 3 ปีที่แล้ว

      @@criped3251 Sup

  • @omtripathi5
    @omtripathi5 3 ปีที่แล้ว

    Hello sir I am 12grade student and jee aspirant

  • @TeamNolex
    @TeamNolex 3 ปีที่แล้ว +1

    Interesting...

  • @None-vb4vr
    @None-vb4vr 3 ปีที่แล้ว

    When are you coming to our school

  • @Serendipity-nh2uk
    @Serendipity-nh2uk 3 ปีที่แล้ว

    I- I’m early........😌💅

  • @rekhabansal2182
    @rekhabansal2182 3 ปีที่แล้ว

    You are teaching wrong tricks to my brother he is changed and I don't like that 😡

  • @orni2throrinque105
    @orni2throrinque105 3 ปีที่แล้ว

    First, but understood nothing