Alternating Series, Types of Convergence, and the Ratio Test

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  • Опубликовано: 3 ноя 2024

Комментарии • 50

  • @c001pers0n
    @c001pers0n 3 года назад +93

    Kinda funny how you explain concepts better in 12 minutes than multiple hours of lecture from my professor.

    • @banaanpropaan9344
      @banaanpropaan9344 10 месяцев назад +5

      Professors/lecturers usually provide proof for whatever math they discuss, which takes significantly more time

    • @carmenouzon6690
      @carmenouzon6690 6 месяцев назад

      Actually crazy

    • @carmenouzon6690
      @carmenouzon6690 6 месяцев назад

      @@banaanpropaan9344there are proofs on here that are explained in 10 minutes and better than 2 hour explanations

  • @brysonmutinda5280
    @brysonmutinda5280 2 года назад +15

    Simply the BEST proffesor,you make difficult things simple

  • @rirhassan6355
    @rirhassan6355 3 года назад +7

    just to let u know ..u explain much better than my uni professor ....u r so good .........i understood all of it in 12 mins.......

  • @hugoteupel8382
    @hugoteupel8382 8 месяцев назад +2

    I’m writing math and physics exams this semester and I can say it’s all self-taught thanks to you😂much love

  • @choo1030
    @choo1030 4 года назад +8

    I honestly can't believe I've purchased a $150 textbook for contents that could be boiled down in 2 days worth of lecture videos. I'm not saying textbook is useless. But textbook has its limit as it cannot show the reader animations of how some things are done.
    Textbook is really only needed for practice problems.

  • @samirouhani
    @samirouhani 5 месяцев назад +1

    Thanks a lot. Just one point, from what I've been studying, I've learned that the AST only tells us whether an alternating series is convergent or not, and it doesn't tell us anything about its divergence.

  • @risinglabyrinth5977
    @risinglabyrinth5977 8 месяцев назад +1

    You scared me on question four of the comprehension test, you had me thinking I was supposed to tetrate XD! Thanks for these videos Professor Dave, these actually really help and give some intuition on these topics.

  • @gokuldath6084
    @gokuldath6084 4 года назад +12

    You're the best in the business, thank you

  • @sameersaifi3300
    @sameersaifi3300 18 дней назад +1

    I Am from India🇮🇳 I totally understand the topic

  • @rolofiend
    @rolofiend 4 года назад +4

    You're actually a savior. Holy moly.

  • @allo9228
    @allo9228 6 лет назад +12

    Hope you're doing well Professor ☺️

  • @Kiky_MedPhysicist
    @Kiky_MedPhysicist 2 месяца назад

    Thank you sir for your dedication! 🙏

  • @NeymarJR-du9rb
    @NeymarJR-du9rb 6 лет назад +1

    Thank you

  • @ivowehsely9131
    @ivowehsely9131 9 месяцев назад

    I love you professor Dave!

  • @gp2580
    @gp2580 6 лет назад +1

    Very interesting - always enjoy your videos - thank you

  • @unknownbeing8222
    @unknownbeing8222 4 года назад +12

    Im now studying mathematics lol, i never thought i would do this.

    • @demonnogo
      @demonnogo 3 года назад +4

      Same, lol! I literally have no need or reason to but it's something that I feel compelled to do.

    • @ian.ambrose
      @ian.ambrose 2 года назад +1

      @@demonnogo You study math just because you feel like so? Woah this stuff you are studying is hard. Knowing that people study math for fun is scary.

    • @klasta2167
      @klasta2167 Год назад

      @@ian.ambrose Im studying for fun too, im 16 lol 💀

  • @zhoud2005
    @zhoud2005 3 года назад

    Great lectures, really enjoyed them. thanks

  • @ian.ambrose
    @ian.ambrose 2 года назад

    Thank you Professor.

  • @bapisaha1766
    @bapisaha1766 6 лет назад +1

    Thank you professor

  • @محمودحقياسماعيلرشيد
    @محمودحقياسماعيلرشيد 3 года назад +5

    the minute 4:40 it is not 16/70 it is 16/68

  • @roronoazoro6153
    @roronoazoro6153 3 года назад +6

    At the example at 4:38 the number 1/5 = 0.2 and 4/12 = 0.3 which is larger. The terms don't get smaller. How can this series converge?

    • @thesakinator7639
      @thesakinator7639 3 года назад +1

      thats why its called conditionally convergent, because its convergency hinges on the fact that the terms ascilate from positive to negative so the sum does in fact get smaller and smaller

    • @DarinBrownSJDCMath
      @DarinBrownSJDCMath 2 года назад +2

      Because any finite number of terms don't affect convergence, all that is required is that the terms are *eventually* decreasing, i.e. b_(n+1) = k for some k. This is something that happens a lot of the time, and it was glossed over in the video. You can check the terms are eventually decreasing by showing the derivative of x^2/(x^3 + 4) is eventually negative.

  • @subforsubcommunitycenter6961
    @subforsubcommunitycenter6961 4 года назад +2

    Please add all the details about limits

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  4 года назад +3

      that's in another video earlier in the calculus playlist

    • @NewWesternFront
      @NewWesternFront Год назад

      @@ProfessorDaveExplains sir please but what is 2+2 and how to prove it sir please sir

  • @honeydevaang732
    @honeydevaang732 2 года назад +1

    so as i understand, the alternative series and all the series associated with the calculus, we only need to find if they are convergent or divergent. but why do we have to do so? what is the relevance of convergence and divergence? maybe it could sound silly but this is my first interaction with the calculus so please pardon me for that.

    • @NewWesternFront
      @NewWesternFront Год назад

      good question. I looked it up and the main answer i found was basically "to help you with even higher level math." whelp.

  • @sciencedude2355
    @sciencedude2355 22 дня назад

    how does the sum of (-1)^(n-1)/n converge if the sum of 1/n diverges?

  • @ramiltaghiyev9712
    @ramiltaghiyev9712 Год назад

    7:53 guys, why is the series on the right divergent? I heard about the p-series

  • @Nemoguzapomnit
    @Nemoguzapomnit 5 лет назад +3

    Thx a lot fot that video! About problems at the end of the video: Σ[(-2)^n/3^n] is it relevant just to rewrite it as Σ[(-2/3)^n] and say that: as r=-2/3 and its less then 1, then the serires is converges?

    • @ravitheja012345
      @ravitheja012345 5 лет назад +2

      r=-2/3 and |r|=2/3

    • @carultch
      @carultch 3 года назад

      How do you pronounce the difference among "p", "п", and "π", when discussing mathematics in your language?

    • @Nemoguzapomnit
      @Nemoguzapomnit 3 года назад

      @@carultch we don't use russian letters in math. But anyway "п" sounds like "pæ". And about "p" and "π" - in case with "p" we would say "p variable"

    • @carultch
      @carultch 3 года назад

      @@Nemoguzapomnit Ok, that makes sense.
      Greek speakers dislike the fact that English speakers shift the vowel when referring to π, so that it sounds like pie. But we have to do that, otherwise both p and π would sound identical, like the word "pea". I found out that they say their own π to sound like like pea, and the Latin p like "pay", as it is most commonly named in languages that use Latin letters.
      I asked you, because I thought a similar issue might persist in your language, except with three different versions of the letter with very similar names.

    • @Nemoguzapomnit
      @Nemoguzapomnit 3 года назад

      @@carultch it could be but we mostly never use "p" variables

  • @yourfutureself4327
    @yourfutureself4327 Год назад +1

    💚

  • @newtoniangaming4832
    @newtoniangaming4832 3 года назад +3

    10:51 but if we just apply
    limit n tends to infinity to (1+1/n)^n we get
    = (1 + 1/infinity)^infinity
    = (1+0)^infinity
    = 1
    so test must be inconclusive rather than divergent right?
    Please correct me if I am wrong.

    • @kjl3080
      @kjl3080 3 года назад

      One word:
      E

    • @DarinBrownSJDCMath
      @DarinBrownSJDCMath 2 года назад +1

      This is why it's terrible when teaching limits to students just learning, to do things like "plugging in infinity", as around the 5:00 mark. This kind of sloppy calculation is okay if you're experienced with limits and indeterminate forms, but it often leads students to wrong conclusions as you've done here. To answer your question, 1^(infinity) is an indeterminate form, and we cannot conclude any value for the limit. (1 + 1/n)^n does converge to e.

    • @kpkrkr4038
      @kpkrkr4038 Год назад

      Same answer I get

  • @kpkrkr4038
    @kpkrkr4038 Год назад

    What is the use of series?

    • @xarlition
      @xarlition 7 месяцев назад

      the simplest example is drug dosage calcs

  • @Dkdkxncnchz
    @Dkdkxncnchz 3 года назад

    best