Sequences, Factorials, and Summation Notation

แชร์
ฝัง
  • เผยแพร่เมื่อ 23 ธ.ค. 2024

ความคิดเห็น • 86

  • @farhanahmed2508
    @farhanahmed2508 7 ปีที่แล้ว +119

    *He knows about all kinds of stuff... Professor Dave Explains!* Love it.

    • @science-y9209
      @science-y9209 3 ปีที่แล้ว +4

      Well it's "he know A LOT about all kinds of stuff..."

    • @bobby9108
      @bobby9108 3 ปีที่แล้ว +7

      You forgot the "woom" at the end

    • @charliechuma8061
      @charliechuma8061 ปีที่แล้ว +1

      Yah,but it doesn't mean shit if he can't explain it

    • @farhanahmed2508
      @farhanahmed2508 ปีที่แล้ว +1

      @@charliechuma8061 He's got a whole channel explaining it

    • @Tusharplays69
      @Tusharplays69 ปีที่แล้ว

      ​@@farhanahmed2508i like how you replied to a reply that's been done almost 5 years after you commented.

  • @ConceptualCalculus
    @ConceptualCalculus 4 ปีที่แล้ว +17

    Your comprehension check at the end uses the word "series," but what you have there are sequences. A sequence is a list. A series results from adding the numbers in the list together.

  • @connorconnor2421
    @connorconnor2421 4 ปีที่แล้ว +32

    For factorials, the sequence rule is:
    a(n) = n * a(n - 1).

    • @josefkay5013
      @josefkay5013 ปีที่แล้ว +6

      As long as you define a(0) := 1

  • @MiltosPol-qn3zh
    @MiltosPol-qn3zh 7 ปีที่แล้ว +17

    I was waiting for this video a lot of time. I finally understood what does this sigma means.

    • @SteelBB9
      @SteelBB9 หลายเดือนก่อน

      ITS ME I AM THE SIGMA

  • @saketpanigrahi
    @saketpanigrahi 4 ปีที่แล้ว +9

    9:32 we can add and find sum =-1/12

  • @teamSwaleOfficial
    @teamSwaleOfficial 6 หลายเดือนก่อน +1

    9:31 mathematician ramanujan from India gave the theorem regarding the sum of all the natural numbers upto infinity and that was. -1/12 it can be confusing that how can the sum of natural numbers be a negative fraction but this is the magic of srinivasan Ramanujan. Please don't say after today that numbers till ♾️ can't be added. And thank you for such an amazing video.♥️

    • @trhll5635
      @trhll5635 หลายเดือนก่อน

      Srinivasa Ramanujan’s answer is -1/12, because his summation method isn’t both linear and stable, and so what’s most likely intended by Dave is that if you tried to use a linear and stable summation method towards the series 1 + 2 + 3 …, then you will not have any finite solution, and this makes sense in the context of Professor Dave’s mathematics tutorials, as he hasn’t taught anything before this video about non-linear and unstable summation methods

  • @RedRahiq
    @RedRahiq หลายเดือนก่อน +1

    2:41 Isn't each term the double plus one of the previous ? Or that there is no sequence with that type ?

  • @thatsnotme3235
    @thatsnotme3235 5 ปีที่แล้ว +7

    Would you mind adding this to the calculus playlist??? I was wondering why I hadn't watched this before!

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  5 ปีที่แล้ว +7

      well the introduction to these concepts is taught in algebra, so in the math playlist this happens way before calculus, i figured just linking to it with a card would be enough!

  • @ivoryas1696
    @ivoryas1696 ปีที่แล้ว +1

    Might I mention how *truthfully **_based_* it is that Dave teaches sequences so early? I didn't these things in college and they feel _largely_ out of place in their conceptual simply being introduced *_after_* limits...

  • @olivernardbagay318
    @olivernardbagay318 2 ปีที่แล้ว +4

    well explained! helped me a lot!

  • @kai.acadventure
    @kai.acadventure 3 หลายเดือนก่อน

    Could you explain whether 0 considers an even number? it makes me confused at 1:05

  • @MiltosPol-qn3zh
    @MiltosPol-qn3zh 7 ปีที่แล้ว +6

    One question. What does i=1(for example) under sigma means???

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  7 ปีที่แล้ว +6

      it means start the summation at i = 1, so you start by plugging in 1 and go from there!

    • @MiltosPol-qn3zh
      @MiltosPol-qn3zh 7 ปีที่แล้ว +3

      Professor Dave Explains Thanks,professor!!!!! Are you going to make a tutorial about capital pi???

  • @yuqingcai3447
    @yuqingcai3447 2 ปีที่แล้ว +3

    Thank you, sir! You are literally saving my life

  • @AllYourMemeAreBelongToUs
    @AllYourMemeAreBelongToUs หลายเดือนก่อน

    This is actually really good.

  • @_Ten_
    @_Ten_ 3 ปีที่แล้ว +1

    Thanks for the video. I'm a little confused at 2:20 . How does 2 * 3 to the N power - 1 give us 18 or 54?. Is N the term number?

    • @Name-is2bp
      @Name-is2bp 2 ปีที่แล้ว

      2 * 3 ^ (1 - 1) = 2 * 3 ^ (0) = 2 * 1 = 2
      2 * 3 ^ (2 - 1) = 2 * 3 ^ (1) = 2 * 3 = 6
      2 * 3 ^ (3 - 1) = 2 * 3 ^ (2) = 2 * 9 = 18
      2 * 3 ^ (4 - 1) = 2 * 3 ^ (3) = 2 * 27 = 54
      ....and so on...

    • @chadani4768
      @chadani4768 2 ปีที่แล้ว +1

      Yes

  • @memeingthroughenglish7221
    @memeingthroughenglish7221 ปีที่แล้ว +1

    Your explanation of e was really cool! Can you make a really in-depth video about e? I feel like it's everywhere, but still kind of mystifying. The same with ln.

    • @ivoryas1696
      @ivoryas1696 ปีที่แล้ว +1

      memeingtheoughenglish7221
      Tbh, yeah.
      I saw it in, like, _one_ class in highschool.
      For such an incredible number as it's often touted, doesn't seem to receive proper treatment until softmore undergrad.
      Like James Maxwell.

  • @OnursDressT
    @OnursDressT 7 ปีที่แล้ว +1

    this is a very good introduction to analysis at uni

  • @Nemoguzapomnit
    @Nemoguzapomnit 6 ปีที่แล้ว +4

    Thx for that video. How you see the patterns for series?

  • @allynreign433
    @allynreign433 3 ปีที่แล้ว +2

    hii, i would like to ask if i can find the sigma notation ‘E’ with using only the series, if that makes sense. for example. (2,4,6,8,10) i have to find the ‘E’ of this series. is there a formula to find a sigma notation with using only the series?

  • @Pegisus2501
    @Pegisus2501 ปีที่แล้ว +2

    Totally Awesome Prof. Dave. 🥳 You've made it so easy to understand. 🤩 I'm no longer scared of math! 🥳 The college textbooks don't even compare to what you give us here. 😊 I can finally see myself understanding computer graphics! 🤩 Thank you so much! 🥰🎉👍🏽💻

    • @ivoryas1696
      @ivoryas1696 ปีที่แล้ว +2

      Pegisus2501
      "I'm not longer scared of math"
      A blessed sentence if _I've_ seen one!

  • @RadoHudran
    @RadoHudran 3 ปีที่แล้ว

    6:09 How do you know what a1, a2, ... is equal to if it wasn't specified?

    • @RadoHudran
      @RadoHudran 3 ปีที่แล้ว

      Nobody said a(n)=n

    • @DefinitelyNotFelis.
      @DefinitelyNotFelis. 8 หลายเดือนก่อน

      Yeah, it was the only thing I didn't quite understand from this lesson.

  • @sweatydood5118
    @sweatydood5118 7 ปีที่แล้ว +8

    Could you do some multivariable calculus?

  • @zahriddinbahodirov9520
    @zahriddinbahodirov9520 ปีที่แล้ว

    I love your lessons, thank you, inshallah I'll soon learn physics course too

  • @lucas5262-h1y
    @lucas5262-h1y 3 ปีที่แล้ว

    So I got a different answer for 1) a1 + 3(n-1) = an
    Would that be wrong? It still works but I think I over complicated it.

  • @Rokanlevio
    @Rokanlevio 11 หลายเดือนก่อน

    when i have the sigam notation i always use i in stead of n is this a problem ?

  • @vedansh7010
    @vedansh7010 2 ปีที่แล้ว

    Professor Dave for the first comprehension question can the answer be :: an-1 +3?

  • @LloydSMITH
    @LloydSMITH 3 ปีที่แล้ว +9

    Very simple Actually ! : )

    • @primalpiano7580
      @primalpiano7580 3 ปีที่แล้ว +3

      Lloyd Smith you have the Coolest channel ever !

  • @jamesb9567
    @jamesb9567 3 ปีที่แล้ว +4

    After some brain mashing, my answer to the second question was "a(n) = (a(n-1) - a(n-2)) + a(n-1) + 4". Seeing the actual answer made me cringe(at myself). Anyways, thanks prof.

    • @Kammerliteratur
      @Kammerliteratur 2 ปีที่แล้ว

      yes, i had exactly the same problem. i figured that the numder, by wich the sequence icreases, increases by 4 each time.

  • @n.v.n.prasad132
    @n.v.n.prasad132 ปีที่แล้ว

    What is the capitalised pi notation? I heard it’s used for summation as well

    • @Vagabond-Cosmique
      @Vagabond-Cosmique ปีที่แล้ว +1

      Capital sigma is for summation, capital pi is for product.
      So Π(n) = n×n×n×n×n×n...
      en.wikipedia.org/wiki/Product_(mathematics)

    • @n.v.n.prasad132
      @n.v.n.prasad132 ปีที่แล้ว

      @@Vagabond-Cosmique thank you!

  • @highflierpriyanka
    @highflierpriyanka 2 ปีที่แล้ว

    Great video!

  • @HussamJihaz
    @HussamJihaz 7 ปีที่แล้ว +1

    Nice vid as always!

  • @unknownbeing8222
    @unknownbeing8222 3 ปีที่แล้ว

    How do we determine the lower limit?

  • @HelloHeloWorld
    @HelloHeloWorld 9 หลายเดือนก่อน

    This was so fun to solve.

  • @joshuanuguse8795
    @joshuanuguse8795 5 ปีที่แล้ว +1

    thanks very much

  • @arinzeanthony7447
    @arinzeanthony7447 ปีที่แล้ว

    My problem is how to write those rational ones in closed form.

  • @mostafamandour5278
    @mostafamandour5278 2 หลายเดือนก่อน

    I got this for second example (n+n)×n 🙂 .., try to plug the number and you will get the exact answer , easy enough 😅

  • @koamivikeledome
    @koamivikeledome ปีที่แล้ว

    Thanks

  • @science-y9209
    @science-y9209 3 ปีที่แล้ว +1

    Something is definitely missing..cuz i didn't get it at all.. unlike your previous videos..even the ones on calculus

  • @Soupy_loopy
    @Soupy_loopy 5 ปีที่แล้ว +3

    This reminds me of the time when I had a good comment

  • @philmaguire4042
    @philmaguire4042 11 หลายเดือนก่อน

    Straight away I’m lost. What is a sub n?

  • @UziMan-Science-Math
    @UziMan-Science-Math 2 ปีที่แล้ว +1

    Can e be expressed like this?

    Σ (1/n!)
    n=1

  • @tyranttitanium5721
    @tyranttitanium5721 4 ปีที่แล้ว +3

    Came for the flat earth videos, stayed for this.

  • @tGoldenPhoenix
    @tGoldenPhoenix 3 ปีที่แล้ว

    Done.

  • @serbrad6426
    @serbrad6426 ปีที่แล้ว

    my humble respect to Sir Isaac Newton

  • @AyisatLawalShittu
    @AyisatLawalShittu 4 หลายเดือนก่อน

    I got no comprehension questions right

  • @sad_man_no_talent
    @sad_man_no_talent ปีที่แล้ว

    he knows stuff but not a lot of stuff

  • @enriquesalazar2538
    @enriquesalazar2538 3 ปีที่แล้ว

    I got lost after sequence

  • @mustafasaber5076
    @mustafasaber5076 8 วันที่ผ่านมา

    n + 3
    ???
    n.n! + n

  • @diganta7
    @diganta7 ปีที่แล้ว

    why the heck does he looks like shakes pear!?

  • @hastylegend1365
    @hastylegend1365 3 ปีที่แล้ว

    feed me more🤩🤩🤩🤩🤩

  • @priencessme6100
    @priencessme6100 7 ปีที่แล้ว +5

    Sir😂😂😂😂 I can't understand do u all tym make just videos.u know I...think that when tym come I will study this stuff now I HV to see first my maths syllabus maybe so I really not interested in ur vid sorry to say

    • @science-y9209
      @science-y9209 3 ปีที่แล้ว +1

      Please brush up your english

    • @RedRahiq
      @RedRahiq 29 วันที่ผ่านมา +1

      Then don't come here. What's ur problem?

  • @nameisfarabi4596
    @nameisfarabi4596 2 ปีที่แล้ว

    Ughhhhhhhhhhhhhhhhhhhhhhhhhhhhh

  • @janedoes5903
    @janedoes5903 4 ปีที่แล้ว

    He didn't explain well. Didn't explain much at all just stated facts.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  4 ปีที่แล้ว +7

      No, I also explained it quite thoroughly. The channel is called Professor Dave Explains. Watch it one more time.

    • @udayseul1535
      @udayseul1535 3 ปีที่แล้ว

      He might be blind. Or dump

  • @GodbornNoven
    @GodbornNoven ปีที่แล้ว +1

    2+3(0)2+3(1), 2+3(2)
    n=0
    2+3n
    2,8,18,32
    Let's divide by 2
    1,4,9,16,25
    2n² as n=1 until n
    1,2,6,24,120
    n!