The p-integral Proof (type 1 improper integral)

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  • เผยแพร่เมื่อ 23 ก.ย. 2024
  • This is one of the must-knows in your calculus 2 class, the improper integral of 1/x^p from 1 to inf. We need to find for what values of p will this integral converge. This will be closely related to infinite series later on.
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ความคิดเห็น • 156

  • @VechtMalthos
    @VechtMalthos 5 ปีที่แล้ว +129

    I showed this to my cat. He looked at me funny and walked off.

  • @98danielray
    @98danielray 5 ปีที่แล้ว +54

    just wanna take the time to thank the great educational job you do here

  • @xevira
    @xevira 5 ปีที่แล้ว +62

    The hood went up.. you know things are about to get real.. or complex... or non-elementary... you never really know with calculus.

    • @wnjstudio4907
      @wnjstudio4907 5 ปีที่แล้ว +6

      maybe things are getting series

  • @blackpenredpen
    @blackpenredpen  5 ปีที่แล้ว +68

    Hi~

    • @letsgetiton99
      @letsgetiton99 5 ปีที่แล้ว +3

      Hi

    • @letsgetiton99
      @letsgetiton99 5 ปีที่แล้ว +1

      wanna ask how to integrate indefinitely of 1 over cos (2x) minus cot (2x)
      . im a beginner

    • @steve2817
      @steve2817 5 ปีที่แล้ว

      Hi!

    • @aurithrabarua4698
      @aurithrabarua4698 5 ปีที่แล้ว

      Hello!!!!!

    • @yaleng4597
      @yaleng4597 5 ปีที่แล้ว

      Say.Is it Peyam?

  • @JoshuaHillerup
    @JoshuaHillerup 5 ปีที่แล้ว +39

    I like doing pintegrals

    • @ffggddss
      @ffggddss 5 ปีที่แล้ว +1

      So, you have a pinterest in them?
      Fred

  • @abrarshaikh2254
    @abrarshaikh2254 5 ปีที่แล้ว +7

    You can also prove that using P-series (zeta function)
    As series is convergence for p>1 only , hence integral will be also convergence for same

  • @roderickwhitehead
    @roderickwhitehead 5 ปีที่แล้ว +33

    No joke, my cat just watched this video with me.

    • @blackpenredpen
      @blackpenredpen  5 ปีที่แล้ว +1

      R.C. Whitehead nice!!!!!

    • @pinklady7184
      @pinklady7184 5 ปีที่แล้ว

      Your cat loves BlackPenRedPen himself.

  • @thefallinglink
    @thefallinglink 5 ปีที่แล้ว +14

    I expected it to converge for p>1 because this problem looks so similar to the p-series convergence test, but as an integral rather than a series. I'm guessing the connection is how integrals can be defined by Riemann sums with infinite rectangles, which is an infinite series?

    • @CharlesPanigeo
      @CharlesPanigeo 5 ปีที่แล้ว +2

      You are correct. Look up the integral test for convergence.

    • @98danielray
      @98danielray 5 ปีที่แล้ว +1

      pretty much

  • @srpenguinbr
    @srpenguinbr 5 ปีที่แล้ว +15

    left a like and put in my Watch later playlist

  • @drpeyam
    @drpeyam 5 ปีที่แล้ว +23

    Haha, that’s what I call the Peyam test in class 😄

  • @hauler-hx6gw
    @hauler-hx6gw 5 ปีที่แล้ว +6

    Here's a problem given to me in a math competition I had today that literally no one figured out in time
    Let lzl=5 and Im {z}>0. If the distance between (1+2i)z^2017 and z^2019 is maximized, then determine Re{z^4} + Im{z^4}
    Reply for correct answer if needed

    • @Babidi123
      @Babidi123 5 ปีที่แล้ว

      Is answer -875?

    • @Rsharlan3
      @Rsharlan3 5 ปีที่แล้ว

      I get 125.

    • @mrmartin988
      @mrmartin988 5 ปีที่แล้ว

      Pretty sure z=5exp(I*pi/3), sound right?

  • @beril7568
    @beril7568 3 หลายเดือนก่อน

    Sir you are like a lifesaver calculus angel. Thank u very much😊

  • @TheNachoesuncapo
    @TheNachoesuncapo 5 ปีที่แล้ว +12

    You are such a good teacher!are you still running marathons?

    • @blackpenredpen
      @blackpenredpen  5 ปีที่แล้ว +2

      Nacho I am. March 24th, LA marathon!

    • @TheNachoesuncapo
      @TheNachoesuncapo 5 ปีที่แล้ว

      @@blackpenredpen YAY!!great to hear

    • @mike4ty4
      @mike4ty4 5 ปีที่แล้ว

      @@blackpenredpen Why do you do that _AND_ the maths stuff instead of just one XOR the other? Is it NECESSARY to do both instead of just one XOR the other? Are you a BAD person if you only do one, but not the other?

    • @tempestandacomputer6951
      @tempestandacomputer6951 4 ปีที่แล้ว

      @@mike4ty4 what?

  • @likris6607
    @likris6607 5 ปีที่แล้ว +1

    This is lifesaving ! I know my cal II test tmr will have at least one question related to this !!!

  • @NavyBlueMan
    @NavyBlueMan 5 ปีที่แล้ว +1

    Here's a question, I just thought of it and don't even know if it's remotely possible to solve, I haven't had time to address it so thought I'd just drop it here:
    The sum from n=0 to infinity of the INTEGRAL of 0 to n of 1/n!
    It reuses n 3 times and so I'm not even sure how someone could approach it but still thought it would be worth asking just for fun. Maybe change it from n going to infinity to 1000 or something a bit easier to approach.

  • @wouterdeniz
    @wouterdeniz 5 ปีที่แล้ว +6

    Know thy integrations and believe thy limits - Chain Lu (2019)

  • @goitomgebremeskel-c9o
    @goitomgebremeskel-c9o 8 หลายเดือนก่อน

    i appreciate this expression because you made it simple though it seems difficult!!!!!!!!!!!

  • @leesin1077
    @leesin1077 5 ปีที่แล้ว +3

    This reminds me a bit of the geometric series or atleast some sort of special case of it. Is there a connection?

  • @nolann2382
    @nolann2382 3 ปีที่แล้ว +1

    he explains this way better than my teacher did I finally somewhat have an understanding of this

  • @rockyk6805
    @rockyk6805 5 ปีที่แล้ว +1

    This is a really good video man! Nice work!!

  • @viridianatirado5374
    @viridianatirado5374 4 ปีที่แล้ว +1

    my go to youtube channel to pass this calc 2 course!

  • @XXgamemaster
    @XXgamemaster 5 ปีที่แล้ว +3

    I still find it very counterintuitive that the p = 1 case diverges. The area under 1/x gets smaller as x goes to infinity so it looks like it should indeed converge. But I guess not...🤔

    • @ffggddss
      @ffggddss 5 ปีที่แล้ว +4

      It diverges, but ve-e-e-ery slowly - logarithmically, in fact.
      He's apparently going to show in a later video, how this integral ("p-integral") helps analyze the behavior of the p-series
      ∑₁⁰⁰(1/nᵖ)
      using what is called "the integral test." When p=1, the series is called the harmonic series, and it too diverges logarithmically.
      This is counterintuitive for the same reason you gave for the integral.
      But in fact, there's a famous constant that is defined by having the integral and the series "run alongside each other" all the way to ∞.
      The Euler-Mascheroni constant is defined by:
      γ = lim [ ∑₁ᵏ(1/n) - ln(k)]
      k→∞
      Its value is about 0.577... (You may recognize this as the first 3 digits of tan 30º = 1/√3, but, alas, the two don't match after 3 digits.)
      Fred

  • @hauler-hx6gw
    @hauler-hx6gw 5 ปีที่แล้ว +2

    Hey, today I went to a math competition and there was this one frq that was really confusing. It had 2 equilateral triangles and a line going through. With those we are supposed to prove two lines intersecting are pi/3
    At first it looked simple but then turned out to be seemingly impossible to prove.
    I later asked about it and it had something to do with the complex plane somehow.
    Would you be able to figure out what I am talking about and make a video on how to do it

  • @RTD553
    @RTD553 10 หลายเดือนก่อน +1

    You broke a lot of pure maths rules there mate!

  • @pachu72lee57
    @pachu72lee57 3 ปีที่แล้ว

    Thank you so much, I was wondering what my professor was doing but now I get it.

  • @STIVESification
    @STIVESification 5 ปีที่แล้ว

    I guess you could you exponent of convergence to find out for which power it converge which is equals lambda+1

  • @quantumcity6679
    @quantumcity6679 5 ปีที่แล้ว +2

    Awesome video but I think you forgot to switch off AC !!........no?
    Or Something alse?? 🤔🤒
    ....little help needed... How expand (4a+5b+6c+.....8e )===.......if a, b, c be the positive integers ?🤑

  • @yoonjuliagil
    @yoonjuliagil 2 ปีที่แล้ว +1

    Thank you for such an amazing video! One question, does the first integral, where p=1, have anything to do with the p-value test (series)?

    • @u36reck63
      @u36reck63 ปีที่แล้ว

      yes, he is demonstrating in the video how it is known that the p-series converges for p > 1

  • @MyNordlys
    @MyNordlys 3 ปีที่แล้ว

    On the same way, serie from 1 to infinite of 1/n diverges and serie from 1 to infinite of 1/n² converges.

  • @habibhassan4015
    @habibhassan4015 5 ปีที่แล้ว +3

    Just did this problem in class on Friday.

  • @johntelegdy105
    @johntelegdy105 5 ปีที่แล้ว +1

    What about 1>p> 0 ? Is p an integer?

  • @schumensch
    @schumensch 5 ปีที่แล้ว

    I know that it's not really 5he right video to ask under, but I really don't understand one thing. If you have a definite integral and want to solve it, by using a trig substitution, then you would also have to change the bounds of it, not just the inside. But let's say the integral is from x=-1 to x=1 and you want to bring it to the theta world. With the substitution e.g. x = cos (theta). So you have 1/-1 = cos (theta), then for both 1 and - 1 you have an infinite amount of theta's to choose from. Do you you always have to choose the principal values? How does the choice of one affect the other? Thanks to everyone in advance!
    PS : I'm a 13 year old from Germany, so if I don't have perfect grammar or spelling or I have a flaw in my logic... Just don't be rude. :)

  • @drdonaldduck
    @drdonaldduck 5 ปีที่แล้ว +1

    Hi, how can I send you a message? I didn't find any email addresses...

  • @Fatih-hy7jj
    @Fatih-hy7jj 4 ปีที่แล้ว

    What I do not get is that how can that area diverge? It can obviously be seen that it gets smaller and smaller, how come it diverges? I understand all the mathematical operations except for this.

  • @yunncchen377
    @yunncchen377 3 ปีที่แล้ว

    x--> infinity, lim 1/(x^(p)) -->0, if p>0 or p > 1, how about p=0.01 > 0, the limit will be 0, can you show me the proof?

  • @PaGow
    @PaGow 4 ปีที่แล้ว

    I saw this video last year, before I was doing calculus and I would never guess that I would need it today😅
    Man...life is funny😂

  • @alegian7934
    @alegian7934 5 ปีที่แล้ว +1

    blackpenredpen, great vid :D also, Im learning about sums and series in university and I need help. Are there any helpful videos on youtube?

  • @JoseShajiOfficial
    @JoseShajiOfficial 3 ปีที่แล้ว

    thank you so much!

  • @Ivan_1791
    @Ivan_1791 5 ปีที่แล้ว +1

    By the way, that integral is equal to 1/(p*ln(p)) for p

  • @alphonsetyche3278
    @alphonsetyche3278 4 ปีที่แล้ว

    p progression
    1/x^p p=1 harmonic series

  • @markberardi109
    @markberardi109 5 ปีที่แล้ว +1

    Thanks for another interesting video. While watching the video, it occurred to me I never understood why the integral of 1/x equals ln (x) ?

    • @blackpenredpen
      @blackpenredpen  5 ปีที่แล้ว +1

      Mark Berardi
      It's how they defined ln(x) first

  • @sebastianmeier5002
    @sebastianmeier5002 5 ปีที่แล้ว

    Can you upload a video of the repeated exponential graph? It would be very interesting, greetings

  • @krukowstudios3686
    @krukowstudios3686 5 ปีที่แล้ว +2

    More of these videos where you end up with a formula! :D

  • @somanathgoudar6171
    @somanathgoudar6171 5 ปีที่แล้ว

    +blackpenredpen, Hello Sir! Greatly impressed by your content. I have a problem and will be highly obliged if you can address to it.
    Let f: R--»R be a function which is continuous at 0 such that f(0)=1. Also assume that f satisfies the relation for all x:
    f(X) - f(X/2) = 3{(X^2)}/4 + X. Find f(3).
    Thank you.
    Love from India!

  • @chillproductive
    @chillproductive 2 ปีที่แล้ว

    Amazing explanation!

  • @gaminginrealtime1552
    @gaminginrealtime1552 5 ปีที่แล้ว +1

    I am taking my first year of math for my bachelor of science. Do you think I should look out for complex numbers at all?

    • @98danielray
      @98danielray 5 ปีที่แล้ว

      youll get it eventually, but if you want it you can

    • @98danielray
      @98danielray 5 ปีที่แล้ว

      at least the intuition for them js important to have

    • @gaminginrealtime1552
      @gaminginrealtime1552 5 ปีที่แล้ว

      @@98danielrayI've dealt with the likes on the square root of negative 1. However, trig like cos(z) = something. Yikes

  • @서현석-p1l
    @서현석-p1l 5 ปีที่แล้ว

    Can you make a video that evaluate integral x/(e^x-1)dx x=0 to infinity?? Plz

  • @videowatcher192
    @videowatcher192 5 ปีที่แล้ว +1

    U are a machine and i like so much your videos

  • @kingphone8824
    @kingphone8824 5 ปีที่แล้ว

    Hi blackpenredpen I am mohammad Daghimen can you make a vedio to how we can Integrate the cube root of(( (x^3_1) ((over x_1 ) ) I love you alot LOL your channel is my favorite on TH-cam

  • @AronGirmay-l9l
    @AronGirmay-l9l 8 หลายเดือนก่อน

    continue bro you are great

  • @enzoyoussef4440
    @enzoyoussef4440 5 ปีที่แล้ว

    Good job bro from Morocco

  • @connorhall6388
    @connorhall6388 4 ปีที่แล้ว

    Shouldnt there be a 3rd case where p=0?

  • @guguwege1523
    @guguwege1523 3 ปีที่แล้ว

    Thankyou

  • @SartajKhan-jg3nz
    @SartajKhan-jg3nz 5 ปีที่แล้ว +1

    Isn't this the zeta function?

  • @TotallyOKaYProductions
    @TotallyOKaYProductions 4 ปีที่แล้ว

    thank you

  • @emilygrootkarzijn6944
    @emilygrootkarzijn6944 3 ปีที่แล้ว

    thanks for making late night maths fun :)

  • @imenelhakim8020
    @imenelhakim8020 ปีที่แล้ว

    Thanks a lot !!

  • @HornyKangaroo314
    @HornyKangaroo314 5 ปีที่แล้ว +1

    Can p become negative number? Or is it true for only p>1?

    • @XXgamemaster
      @XXgamemaster 5 ปีที่แล้ว +1

      Ayip Hikhok The integral diverges for p less than or equal to 1, so that also applies if p is negative.

    • @HornyKangaroo314
      @HornyKangaroo314 5 ปีที่แล้ว

      @@XXgamemaster ahh thank you.

  • @devananjelito9111
    @devananjelito9111 3 ปีที่แล้ว

    Excellent!

  • @imanolmanzanares5000
    @imanolmanzanares5000 5 ปีที่แล้ว +1

    always believe in the math!! nice video broo

  • @saarike
    @saarike 5 ปีที่แล้ว

    Very nice!

  • @aurithrabarua4698
    @aurithrabarua4698 5 ปีที่แล้ว +3

    Is there very cold out there?? 😂😂😂

  • @19pixels
    @19pixels 3 หลายเดือนก่อน

    Watching this 5 hours before my real analysis exam (I'm not so cooked after all)💀😂

  • @Ironmonk036
    @Ironmonk036 5 ปีที่แล้ว +1

    The man is sporting the hoodie on. 🤪

  • @safouaner-ryfy6060
    @safouaner-ryfy6060 5 ปีที่แล้ว +1

    integrate of cos x/ x

  • @scarbotheblacksheep9520
    @scarbotheblacksheep9520 5 ปีที่แล้ว

    The negative version of the best friend!

  • @youssefbenhachem993
    @youssefbenhachem993 5 ปีที่แล้ว

    Hey guys i need help in an integral : integral from 0 to 1 to 1/(1-x) + 1/lnx dx . Thanks

  • @ianmoseley9910
    @ianmoseley9910 4 ปีที่แล้ว

    diverges when p = 0?

  • @saharhaimyaccov4977
    @saharhaimyaccov4977 5 ปีที่แล้ว +1

    X^(x-1) ?

  • @sripranav
    @sripranav 3 ปีที่แล้ว

    Believe in your limits!

  • @gabrielag1844
    @gabrielag1844 4 ปีที่แล้ว

    Once again, you've saved me :)

  • @quandaledinglegaming9930
    @quandaledinglegaming9930 2 ปีที่แล้ว

    the drip is continous but not differentiable!

  • @Flanlaina
    @Flanlaina 4 ปีที่แล้ว

    Type 1 or type 2?

  • @Polaris_Babylon
    @Polaris_Babylon 5 ปีที่แล้ว +2

    P-Series

  • @asusmctablet9180
    @asusmctablet9180 5 ปีที่แล้ว +1

    So if p is only infinitesimally greater than one, it converges to one over an infinitesimal, which is still infinity. Ok, got it.

  • @fouadsbihi4393
    @fouadsbihi4393 5 ปีที่แล้ว

    Do p=i cmlx

  • @tryphonunzouave8384
    @tryphonunzouave8384 5 ปีที่แล้ว

    Why is this an improper integral ?

  • @alexanderskladovski
    @alexanderskladovski 5 ปีที่แล้ว

    The negative best friend aka the worst friend

  • @rafaellisboa8493
    @rafaellisboa8493 5 ปีที่แล้ว

    PLEASE make complex version, formula for 1/(a+bi)^z

    • @blackpenredpen
      @blackpenredpen  5 ปีที่แล้ว +1

      Ginger Stalin and the limits of integration?

    • @98danielray
      @98danielray 5 ปีที่แล้ว

      the condition is the same

    • @98danielray
      @98danielray 5 ปีที่แล้ว

      converges for Re(z)>1

  • @ThePharphis
    @ThePharphis 5 ปีที่แล้ว

    @5 mins: or just add p to both sides you crazy man!

  • @matthewchuang6707
    @matthewchuang6707 5 ปีที่แล้ว

    I screwed up my math interview in December because of this question.... damn

  • @luisramrod9121
    @luisramrod9121 5 ปีที่แล้ว

    This is in my calculus book.

    • @budtastic1224
      @budtastic1224 5 ปีที่แล้ว

      Dr. Chow is in ur calc book?! Amazing!

    • @luisramrod9121
      @luisramrod9121 5 ปีที่แล้ว

      @@budtastic1224 who is chow?

    • @budtastic1224
      @budtastic1224 5 ปีที่แล้ว

      @@luisramrod9121 bprp

  • @bandamkaromi
    @bandamkaromi 5 ปีที่แล้ว +4

    hi. all. :-)

  • @kingphone8824
    @kingphone8824 5 ปีที่แล้ว +1

    I showed it to my dog it run scared heeeeeeeee

  • @aidambo1522
    @aidambo1522 ปีที่แล้ว

    matache broo i got it bro

  • @andres.robles6
    @andres.robles6 5 ปีที่แล้ว

    Hi5

  • @rakhimondal5949
    @rakhimondal5949 5 ปีที่แล้ว +1

    He's dope

  • @richardfredlund3802
    @richardfredlund3802 5 ปีที่แล้ว

    my cat just not getting it....perhaps I need to show more times :)

  • @samuelvernola2609
    @samuelvernola2609 5 ปีที่แล้ว

    I love you

  • @AlphaTaurinet
    @AlphaTaurinet 5 ปีที่แล้ว +1

    你太棒了

  • @ayishashifam9101
    @ayishashifam9101 5 ปีที่แล้ว

    U r very fast...

  • @tehyonglip9203
    @tehyonglip9203 5 ปีที่แล้ว

    Mathematician are triggered seeing him plugging in infinity like a number instead of using limit.

  • @abdullahsharaawy
    @abdullahsharaawy 8 หลายเดือนก่อน

    ❤❤❤❤❤❤

  • @physicsphysics1956
    @physicsphysics1956 5 ปีที่แล้ว +2

    I like your videos, but please use ln(x) instead of ln|x| for the integral of 1/x. Please delete all of your videos and reupload them but without the absolute value.

    • @Makabaril
      @Makabaril 5 ปีที่แล้ว +1

      physics physics why’s that? The second one is correct for a larger domain than the first

    • @blackpenredpen
      @blackpenredpen  5 ปีที่แล้ว

      Jacob Jeffries I did use ( ) in this video. Since I know the interval is pos so no need for abs value.

    • @physicsphysics1956
      @physicsphysics1956 5 ปีที่แล้ว

      @@blackpenredpen Still, that is only for this purpose. Please use ln(x) for integrals in general.

    • @blackpenredpen
      @blackpenredpen  5 ปีที่แล้ว

      physics physics
      How would you integrate 1/x from -3 to -2?

    • @physicsphysics1956
      @physicsphysics1956 5 ปีที่แล้ว

      @@blackpenredpen -0.4055

  • @sei-bay
    @sei-bay 2 ปีที่แล้ว

    Emmy good

  • @noahshomeforstrangeandeduc4431
    @noahshomeforstrangeandeduc4431 5 ปีที่แล้ว

    Hi

  • @Ivan_1791
    @Ivan_1791 5 ปีที่แล้ว +2

    Too easy.

  • @KingV676
    @KingV676 3 ปีที่แล้ว

    Next time do some exercises okay me bro

  • @lambdamax
    @lambdamax 5 ปีที่แล้ว

    P-integrals on pinterest