Group Theory 6, order of a Group, order of an element

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  • เผยแพร่เมื่อ 4 ต.ค. 2024

ความคิดเห็น • 48

  • @liltv2012
    @liltv2012 10 ปีที่แล้ว +3

    Your videos are very helpful. Your explanations are clear and understanding. Thank you very much!

  • @LadislauFernandes
    @LadislauFernandes  11 ปีที่แล้ว +5

    tks for watching my videos.

  • @koozdra
    @koozdra 10 ปีที่แล้ว +3

    Really enjoying the series so far. Just wanted to let you know that this video appears out of order in your "Group Theory" playlist. I'm guessing it was not intentional because the next video (7) introduces subgroups.

    • @LadislauFernandes
      @LadislauFernandes  10 ปีที่แล้ว

      Tks a Lot Dimitri, I will check that....

    • @LadislauFernandes
      @LadislauFernandes  10 ปีที่แล้ว

      Please check if it is ok now

    • @koozdra
      @koozdra 10 ปีที่แล้ว +1

      LadislauFernandes It is perfect now. Thank you very much.

    • @LadislauFernandes
      @LadislauFernandes  10 ปีที่แล้ว

      Dimitri Tishchenko I am the one who is grateful

  • @LadislauFernandes
    @LadislauFernandes  11 ปีที่แล้ว +7

    11^2 (mod15) right? since you are in U(15)... so just get 121 and subtract 15 till you get inside U(15)... you will do this 8 times
    or, 121 - 15 x 8 = 1
    tks for watching the videos

    • @HAWI-SO
      @HAWI-SO 7 ปีที่แล้ว +1

      I think it needs some correction. The order of a group is its carnality for example the order of Z10 is 10 these are {0,1,2,3,4,5,6,7,8,9} the numbers 1,3,7,9, ( the relative primes of 10) are not the orders . They are the group generators.

  • @xoppa09
    @xoppa09 8 ปีที่แล้ว +3

    small mistake
    8:38 16 modulo 15 should be 1
    But i understand you meant to say the order of 4 is 2.
    Great video. So much better than reading an arcane textbook.

  • @cscor
    @cscor 9 ปีที่แล้ว +6

    thank you... modern mathematics made easy...feeling relaxed..

  • @Money__Matters007
    @Money__Matters007 10 ปีที่แล้ว +3

    your videos are really great.please make videos on metric spaces and topology covering proofs as well as practice problems .thanks in advance
    regards

  • @LadislauFernandes
    @LadislauFernandes  11 ปีที่แล้ว +3

    I am giving you a link in the video description ok?
    Its just the elements of Z_n "relatively prime" to n.
    Or the "units" of Z_n
    Imagine you have Z_14 = {0, 1, 2,...13} right? But now you will take only the elements relatively prime to 14, so that will be:
    U(14)={1,3,5, 9,13}
    Not the "prime numbers", e.g., check that 7 is not there.
    I will make a video for that... you are not the first person asking that...

  • @fawzyhegab
    @fawzyhegab 11 ปีที่แล้ว

    yes , since 11 and 14 are relativity prime , this means that there is no number which divide both 11 and 14 except 1.

  • @LokmanMahazer
    @LokmanMahazer 11 ปีที่แล้ว +2

    this much helping in my study

  • @smsthea2z973
    @smsthea2z973 7 ปีที่แล้ว +2

    i know its a stupid question but , how can i find U(n) i m not getting it

  • @ib4609
    @ib4609 9 ปีที่แล้ว +1

    With the order of a group, is it the number of distinct elements or is it just the number of elements?

  • @arundhatipandey1368
    @arundhatipandey1368 4 ปีที่แล้ว +1

    Thank you😊

  • @mansoorakhtar6181
    @mansoorakhtar6181 11 ปีที่แล้ว +1

    dear sir in your video you write u(10)={1,3,5,7,9} what does it called and how this set becomes kindly reply

  • @owusualfredkwabena8929
    @owusualfredkwabena8929 8 ปีที่แล้ว

    am really enjoying the lesson thank you

  • @chunkylover5367
    @chunkylover5367 7 ปีที่แล้ว +2

    So, why don't you actually explain how 7^1=7, 7^2=4, etc... wtf... Why I am so fucking stupid?

    • @m35926
      @m35926 7 ปีที่แล้ว

      modular multiplication, so 7^2 is being represented as 7*7=49 but we're in modulo 15 so 15*3=45 making 49-45=4

  • @HashimAli-2013
    @HashimAli-2013 ปีที่แล้ว

    Great 🙌

  • @emprendeperez
    @emprendeperez 7 ปีที่แล้ว +1

    IB students that sutdy from here for the exams os n14 had the first question all correct

  • @manikanta5551
    @manikanta5551 7 ปีที่แล้ว

    Is there any shortcut to find order

  • @albron2189
    @albron2189 4 ปีที่แล้ว +1

    Great sir how to find number of subgroup of order 2 of a group of order12

    • @LadislauFernandes
      @LadislauFernandes  4 ปีที่แล้ว

      Please check this, hope that helps:
      groupprops.subwiki.org/wiki/Subgroup_structure_of_groups_of_order_12

  • @renupanthangi7029
    @renupanthangi7029 3 ปีที่แล้ว

    Notes lo vunna vidham ga chepparu but explanation correct ga evvale
    Sorry to say this

  • @Scripter
    @Scripter 6 ปีที่แล้ว +1

    3:30 minus 1 thats 3 quick maths.

  • @Maths_Magic_
    @Maths_Magic_ 3 ปีที่แล้ว

    i think i have to follow joseph gallian contemporary abstract algebra

  • @user-mz7fh2hy6x
    @user-mz7fh2hy6x 6 ปีที่แล้ว

    I am looking for tutor.. Is there anyone who can help me for abstract algebra or other math subjects

  • @owusualfredkwabena8929
    @owusualfredkwabena8929 8 ปีที่แล้ว

    thank sir what is the order of [24]

  • @YaWePcGame
    @YaWePcGame 10 ปีที่แล้ว +2

    what do the elements of U(10) come from. why are those elements 1,3,7,9? Thanks

    • @RkeyNirun
      @RkeyNirun 9 ปีที่แล้ว +2

      +YaWePcGame Mod 10 for multiplication. 3*3 = 9, 9*3 = 27 = 7 mod 10, 7*3 = 21 = 1 mod 10, 1 * 3 = 3

    • @xoppa09
      @xoppa09 8 ปีที่แล้ว +5

      U(10) is the set elements under the operation multiplication mod 10 such that each element has an inverse. We can't use the entire set Z10 { 0,1,2,3,4,.. 9} for this group because for example 2x = 1 has no solution in mod 10. But 3x =1 has a solution in mod 10, namely x = 7. Recall that for a set to be a group each element must have an inverse. It turns out, the elements of U(n) are the set of elements relatively prime to n.

  • @LokmanMahazer
    @LokmanMahazer 11 ปีที่แล้ว

    thanks

  • @yakhilijamatia9377
    @yakhilijamatia9377 2 ปีที่แล้ว

    Questions of this ans plz?

  • @you0are0rank
    @you0are0rank 11 ปีที่แล้ว

    would 11 be in U(14) ?

  • @CallMeMantou
    @CallMeMantou 10 ปีที่แล้ว +3

    Thanks for your video!
    Just want to add a correction to the order of 4 at 8:30
    16 modulo 15 is 1. so |4| = 1 , and not 2

    • @yatmingcheung2772
      @yatmingcheung2772 7 ปีที่แล้ว +3

      Jon Tan 4^2 = 16 = 1 (mod 15)

    • @andrewsantamonica6025
      @andrewsantamonica6025 6 ปีที่แล้ว +1

      16 mod 15 is 1, but the order is 2 because 4 needs to be raised to the power of 2 (mod 15).

  • @manisharma421
    @manisharma421 3 ปีที่แล้ว

    Tq

  • @birdhanhansdah8580
    @birdhanhansdah8580 4 ปีที่แล้ว

    How do you

  • @kingomar3668
    @kingomar3668 5 ปีที่แล้ว

    اشرح بالعربي افضل 😉😉

  • @Tradexoffecials
    @Tradexoffecials 27 วันที่ผ่านมา +1

    Worst teacher