Counting Partitions of Sets and Bell Numbers | Combinatorics

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  • เผยแพร่เมื่อ 26 ธ.ค. 2024

ความคิดเห็น • 79

  • @djrkm9281
    @djrkm9281 2 หลายเดือนก่อน +1

    props to ur enthusiasm. If all teachers were as enthusiastic as you know knows maybe we would actually attend the lectures. Thx so much

  • @tomascremaschi1008
    @tomascremaschi1008 2 ปีที่แล้ว +7

    Great explanation thank you! I can also see the passion you have for the subject which is amazing, keep the great work.

    • @WrathofMath
      @WrathofMath  2 ปีที่แล้ว +1

      Thanks a lot, I do my best! Let me know if you have any questions, and if you're looking for more on partitions and Bell numbers - I have a few more related videos...
      Recurrence Relation for Bell Numbers: th-cam.com/video/sPGudyLalmE/w-d-xo.html
      Recurrence proof: th-cam.com/video/abfCpVASfLM/w-d-xo.html

  • @springvibes5344
    @springvibes5344 ปีที่แล้ว +3

    المُنقذ شكرًا جزيلًا.. I said in Arabic that you are Savior, so Thank you very much.

  • @harshporwal8479
    @harshporwal8479 8 หลายเดือนก่อน

    Explanation is crystal clear

  • @solitary6002
    @solitary6002 ปีที่แล้ว +1

    I was introduced to this bell triangle as a way to count the number of possible equivalence relations on a set of n elements.... Back then I didn't know that every possible way to partition a set can be associated with an equivalence relation.

  • @vikasavasthi8346
    @vikasavasthi8346 3 ปีที่แล้ว

    Thanx it help me alot in public service exam for teaching.
    ❤️Love from INDIA 🇮🇳

    • @WrathofMath
      @WrathofMath  3 ปีที่แล้ว

      So glad to hear it, thanks for watching and much love back from the east coast of the USA!

  • @mayurtummewar3312
    @mayurtummewar3312 2 ปีที่แล้ว +1

    ooho 🤩 the outro is fire 🔥🔥🔥

  • @ftherogamer1073
    @ftherogamer1073 11 หลายเดือนก่อน

    Thank you it helped a lot i really like your way of teaching please keep it up i appreciate your work 😊

  • @AnkitKumar-ur2gq
    @AnkitKumar-ur2gq 4 ปีที่แล้ว +2

    Understood in just one go, thank you sir 😁

    • @WrathofMath
      @WrathofMath  4 ปีที่แล้ว +2

      Glad to hear it! Thanks a lot for watching and let me know if you ever have any video requests!

  • @mamaligakimchi
    @mamaligakimchi ปีที่แล้ว

    It was an amazing explanation, thank you so much!

  • @pradeepmondal4943
    @pradeepmondal4943 4 ปีที่แล้ว +1

    Just osssm ❤️❤️❤️❤️loved it ..
    Great explaination ..
    Guys watch this , without any time waste...

    • @WrathofMath
      @WrathofMath  4 ปีที่แล้ว

      Thanks so much, I am glad it helped!

  • @pasqualedippolito3135
    @pasqualedippolito3135 หลายเดือนก่อน

    Great explanation

    • @WrathofMath
      @WrathofMath  หลายเดือนก่อน

      Thank you!

  • @chamudisewmini3421
    @chamudisewmini3421 3 ปีที่แล้ว +2

    I was trying to find this by myself. But now I know I was wrong. Thank you very much for the video 😍

    • @WrathofMath
      @WrathofMath  3 ปีที่แล้ว +1

      Glad it helped, thanks for watching! Being wrong is one of the most interesting parts of math, always satisfying to realize what you're missing when you can't quite crack a problem!

  • @illusion7687
    @illusion7687 2 ปีที่แล้ว

    Great explanation sir❤😇

  • @AManOfMusic
    @AManOfMusic 2 ปีที่แล้ว +4

    I have a question about these Bell numbers.
    I was messing around with the infinite factorial sum for e. 1/n!
    Then , I decided to see what would happen if I replaced 1 with n, so I wrote n/n!, and the answer was e.
    Then, I squared the top n, and the answer I got was 2e.
    Then, I cubed the n, and the answer I got was 5e.
    I kept going with this, and I only got multiples of e: 2, 5, 15, 52, 203, 877, 4140...
    Even with the first two sums I did, 1 is just n^0, and n is n^1, so I get the first two 1's of the sequence.
    Why do these Bell numbers show up with e?

  • @shreshthdimri6412
    @shreshthdimri6412 3 ปีที่แล้ว

    Killer Explanation.

  • @valor36az
    @valor36az 2 ปีที่แล้ว

    Awesome video thanks !

    • @WrathofMath
      @WrathofMath  2 ปีที่แล้ว

      Thanks for watching!

  • @utkarshtripathi2349
    @utkarshtripathi2349 3 ปีที่แล้ว

    Great Explanation! Thank you so much

    • @WrathofMath
      @WrathofMath  3 ปีที่แล้ว +1

      Thank you, so glad it helped! I don't know if you saw my other two lessons on this topic, here they are if not!
      Bell Numbers and their Recurrence Relation: th-cam.com/video/abfCpVASfLM/w-d-xo.html
      Proof of the Recurrence: th-cam.com/video/sPGudyLalmE/w-d-xo.html

  • @mokoepa
    @mokoepa 3 ปีที่แล้ว

    This is gold... Holy Molly...

    • @WrathofMath
      @WrathofMath  3 ปีที่แล้ว

      Thanks for watching! I made a couple other videos on this topic if you're interested.
      th-cam.com/video/sPGudyLalmE/w-d-xo.html
      th-cam.com/video/abfCpVASfLM/w-d-xo.html

  • @farukahmed3179
    @farukahmed3179 3 ปีที่แล้ว

    Great
    Explanatio level is on fire🔥🔥

    • @WrathofMath
      @WrathofMath  3 ปีที่แล้ว

      Thank you! If you want some real fire, check out my math songs! th-cam.com/play/PLztBpqftvzxW7a66b0dJPgknWsfbFQP-c.html

  • @naanungamulla6528
    @naanungamulla6528 2 ปีที่แล้ว

    Amazing trick and teaching is very good attractive

    • @WrathofMath
      @WrathofMath  2 ปีที่แล้ว +1

      Thanks a lot, glad you liked it!

  • @divyadharshini1648
    @divyadharshini1648 3 ปีที่แล้ว

    Very Very useful

    • @WrathofMath
      @WrathofMath  3 ปีที่แล้ว

      Glad to hear it, thanks for watching!

  • @johndoe9659
    @johndoe9659 3 ปีที่แล้ว

    Please provide a geometric and animated proof of WHY adding Stirling numbers of the second kind add up to Bell numbers. Also: please provide a non-recursive, closed formula for the Bell number and make a video that explains the formula in an intuitive way.

  • @ceerie7487
    @ceerie7487 ปีที่แล้ว

    10:14 I get confused on this part
    for the last 2 elements why not add {3},{4} but he then immediately jumps to 3 elements which is 1,2,3?
    Edit: Okay nvm, he added it later on

  • @iitianrupa4513
    @iitianrupa4513 4 ปีที่แล้ว +1

    Please make full vedios and more for all combinatorics topics,thankyou!!😊

    • @WrathofMath
      @WrathofMath  4 ปีที่แล้ว +1

      You're very welcome and thank you for watching! More combinatorics videos are on the way!

  • @hibaamu7234
    @hibaamu7234 3 ปีที่แล้ว

    Awesome sir u teach awesome 👌 👏 👍 😎 😀

    • @WrathofMath
      @WrathofMath  3 ปีที่แล้ว

      Thank you, I do my best! If you're looking for more on partitions and bell numbers, check out my two related videos...
      th-cam.com/video/sPGudyLalmE/w-d-xo.html
      th-cam.com/video/abfCpVASfLM/w-d-xo.html

  • @tirthpatel20
    @tirthpatel20 3 ปีที่แล้ว

    Amazing Explanation! ...Thank you ❤️

    • @WrathofMath
      @WrathofMath  3 ปีที่แล้ว

      Glad it helped! Thanks for watching!

  • @avinashagrahari7106
    @avinashagrahari7106 3 ปีที่แล้ว

    I liked your video...it's very help for us sir...👌👌

    • @WrathofMath
      @WrathofMath  3 ปีที่แล้ว

      Thanks for watching, glad it was helpful! Check out the other two lessons I did on this topic if you're interested!
      th-cam.com/video/sPGudyLalmE/w-d-xo.html
      th-cam.com/video/abfCpVASfLM/w-d-xo.html

  • @mathwizards6785
    @mathwizards6785 4 ปีที่แล้ว

    😍😍😍😍sir amazing explanation

    • @WrathofMath
      @WrathofMath  4 ปีที่แล้ว

      Thank you! I am glad it was clear and let me know if you ever have any questions!

  • @КЫРЫМСДЫШНМЕРЕКЗИШН
    @КЫРЫМСДЫШНМЕРЕКЗИШН 2 ปีที่แล้ว

    What does n choose k mean?

  • @jidebranco5837
    @jidebranco5837 3 ปีที่แล้ว

    Thank you!

    • @WrathofMath
      @WrathofMath  3 ปีที่แล้ว

      No problem - thanks for watching!

  • @bradleyshepard
    @bradleyshepard 3 ปีที่แล้ว

    thanks- well done!

    • @WrathofMath
      @WrathofMath  3 ปีที่แล้ว

      My pleasure, thanks for watching!

  • @MIKL
    @MIKL 3 ปีที่แล้ว

    Thank you ❤️

    • @WrathofMath
      @WrathofMath  3 ปีที่แล้ว

      You’re welcome 😊

  • @matejcataric2259
    @matejcataric2259 ปีที่แล้ว

    Where is your combinatorics playlist?

  • @mathsokparmeshwargurjar5291
    @mathsokparmeshwargurjar5291 3 ปีที่แล้ว

    Awesome

  • @shanedymaevallejos2400
    @shanedymaevallejos2400 3 ปีที่แล้ว

    thanks

    • @WrathofMath
      @WrathofMath  3 ปีที่แล้ว

      No problem, thanks for watching!

  • @griffinbur1118
    @griffinbur1118 2 ปีที่แล้ว

    Well-earned sub from me! Great video

  • @gmjammin4367
    @gmjammin4367 4 ปีที่แล้ว

    Awesome video :)

  • @KkPluto
    @KkPluto ปีที่แล้ว

    broooooooooo thank uuuuuuuuuuuu

  • @neelabhabanerjee8247
    @neelabhabanerjee8247 2 ปีที่แล้ว

    Hi man, I am really struggling with problems of the binomial theorem and pigeon hole principle from this book "A walk through combinatorics, Bona", if possible can you suggest a few good books to start these topics off with? Thank you!

    • @WrathofMath
      @WrathofMath  2 ปีที่แล้ว +1

      I haven't read much straight combinatorics, so I can't say much about that (I have been wanting that particular book though). Proofs by Jay Cummings is a wonderful modern intro to proofs book that devotes some time to the Pigeonhole Principle. But you may not find it any more thorough or useful than what's in Bona's. I am a big fan of Book of Proof, which is a free proofs book you can find online, but I honestly can't recall whether or not it has pigeonhole principle in it. I'd think it would, but I can't actually remember seeing it. I always sing the praises of A First Course in Graph Theory by Chartrand and Zhang, but that's all for Graph Theory, which comes later in the Bona text. I of course have over a hundred videos on graph theory.

    • @neelabhabanerjee8247
      @neelabhabanerjee8247 2 ปีที่แล้ว

      @@WrathofMath yes yes your graph theory proofs help a lot bro. Are you in linkedIn btw? We can connect maybe if you're interested.

    • @neelabhabanerjee8247
      @neelabhabanerjee8247 2 ปีที่แล้ว

      @@WrathofMath Also, you can make a Video on Ferrers shapes if possible they 're pretty interesting thoo

  • @manuxoxo6399
    @manuxoxo6399 4 ปีที่แล้ว

    Niccceeee!! 👑👑👑

    • @WrathofMath
      @WrathofMath  4 ปีที่แล้ว

      Thanks for watching!

  • @МихаилСмирнов-ь6у
    @МихаилСмирнов-ь6у ปีที่แล้ว

    Отлично. Лайк.

  • @shielamaecaballes8913
    @shielamaecaballes8913 3 ปีที่แล้ว

    Hi to my new crush 🥰.please notice me💙 i just love how you simplify things..

    • @WrathofMath
      @WrathofMath  3 ปีที่แล้ว

      Thank you for watching! 😊 Let me know if you ever have any video requests! Elegant simplicity and beauty, math is filled with it!

  • @Subhajit_Paul123
    @Subhajit_Paul123 ปีที่แล้ว

    You didn't explain the recurrence relation.

    • @WrathofMath
      @WrathofMath  ปีที่แล้ว

      th-cam.com/video/sPGudyLalmE/w-d-xo.html

  • @ritam_arya
    @ritam_arya ปีที่แล้ว

    you just showed that the recurrence relation works and all the possibilities of parting a set. i expected an explanation on why is it the way it is. so overall, it's a stupid video.