life changing integration by parts trick

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  • เผยแพร่เมื่อ 3 พ.ย. 2024

ความคิดเห็น • 1.3K

  • @ThJakester897
    @ThJakester897 2 ปีที่แล้ว +4301

    This technique is absolutely crazy. I feel like I now have the confidence to ask my boss for a raise and find a beautiful wife to marry. Thanks, Dr. Peyam.

  • @blackpenredpen
    @blackpenredpen 2 ปีที่แล้ว +2964

    This is actually really cool 😆
    Glad I actually watched it haha

    • @drpeyam
      @drpeyam  2 ปีที่แล้ว +243

      Awwwww thank youuuu!!!

    • @borg972
      @borg972 2 ปีที่แล้ว +74

      Please combine this with the DI method!😺

    • @ILoveMaths07
      @ILoveMaths07 2 ปีที่แล้ว +39

      Nuuuuu! Now bprp will kill his students with these questions!

    • @petereziagor4604
      @petereziagor4604 2 ปีที่แล้ว +4

      Master 😅

    • @pain8117
      @pain8117 2 ปีที่แล้ว +21

      What is this crossover episode? 🧐

  • @nonentity168
    @nonentity168 9 หลายเดือนก่อน +793

    Now the +C is actually useful. Great video

    • @w花b
      @w花b 8 หลายเดือนก่อน +4

      Yup

    • @jaskhetani4631
      @jaskhetani4631 7 หลายเดือนก่อน +1

      So trueee

  • @DrTrefor
    @DrTrefor 2 ปีที่แล้ว +1093

    How did I not know this. My life is changed.

    • @tanish6035
      @tanish6035 2 ปีที่แล้ว +2

      Greetings sir

    • @kiit8337
      @kiit8337 2 ปีที่แล้ว

      Orz here

    • @abhwi
      @abhwi 8 หลายเดือนก่อน

      It's a very normal question in WBCHSE class 12

    • @divinecreation6
      @divinecreation6 7 หลายเดือนก่อน +13

      ​@@abhwiNo one teaches this method in class 12

    • @bhathilal01
      @bhathilal01 5 หลายเดือนก่อน

      same here!!!!!

  • @liamloveslunch
    @liamloveslunch 8 หลายเดือนก่อน +128

    "Arent you glad I found my video? 😁" Yes! So happy!
    Glad to see you so happy about math too :)

  • @gamingroom2541
    @gamingroom2541 8 หลายเดือนก่อน +69

    3:11 “Isnt that nice!” Nice ? NICEEE ??? SIR THAT IS STRAIGHT AMAZING my life is never the same after this

  • @sharpnova2
    @sharpnova2 2 ปีที่แล้ว +594

    I've taught this method to my students for years and it's always made them much better at integrating in general

    • @aarjith2580
      @aarjith2580 2 ปีที่แล้ว +8

      Hey, I have a doubt, Why do we have to choose the same constant at both the places though? for example at 4:47

    • @agustincai
      @agustincai 2 ปีที่แล้ว +1

      symbolab gave me another result in his first integral

    • @kilian8250
      @kilian8250 2 ปีที่แล้ว +1

      A Arjith look at the proof of integration by parts

    • @maximlavrenko1164
      @maximlavrenko1164 ปีที่แล้ว

      @@aarjith2580 because we can't choose different ones. We are plugging in the antiderivative in both places you bum

    • @xinpingdonohoe3978
      @xinpingdonohoe3978 ปีที่แล้ว +3

      ​@@aarjith2580 you integrate 1 and differentiate arctan(√(x+1)). Your derivative of that term is set, but the integral of 1 is x+c. This works for any fixed c. Hence, we fix c=2 as it's most useful to us. This means, each time we use this specific antiderivative of 1, our constant is 2.

  • @floydmaseda
    @floydmaseda 2 ปีที่แล้ว +1451

    Thought the title was click bait.
    It was NOT click bait.
    Life changing, indeed!

    • @drpeyam
      @drpeyam  2 ปีที่แล้ว +50

      Omg hi Floyd!!!

    • @aarjith2580
      @aarjith2580 2 ปีที่แล้ว +2

      @@drpeyam Hey, I have a doubt, Why do we have to choose the same constant at both the places though? for example at 4:47

    • @plislegalineu3005
      @plislegalineu3005 2 ปีที่แล้ว +8

      @@aarjith2580 When you're doing integration by parts, you integrate "dv", and you can add any constant to the v. But if the constants are different we would get v≠v

  • @krischalkhanal2842
    @krischalkhanal2842 2 ปีที่แล้ว +641

    I remember asking teacher, "can we add a constant to *inner integration* in the formula of integration by parts?"
    He told me, "only a single +c can appear in a single integration", which feels so stupid to me now.
    I am so glad I found this video. Kudos to you Dr. Peyam.

    • @skylardeslypere9909
      @skylardeslypere9909 2 ปีที่แล้ว +38

      I think he probably thought you meant a general +C when applying the formula, which I'd also perhaps not recommend because it'll look too messy. But specific constants to make it easier, definitely do it!

    • @sharpnova2
      @sharpnova2 2 ปีที่แล้ว +52

      I'm sure it was more a result of you asking your question unclearly

    • @MrSamshy
      @MrSamshy 2 ปีที่แล้ว +9

      Probably your question wasn’t clear to him, so he meant you don’t add +C within each term.

    • @jakolu
      @jakolu 2 ปีที่แล้ว +3

      @@skylardeslypere9909 that's still a bad answer from the teacher imo, especially without qualification. Of course many teachers won't get into the specifics of derivations and logic because of their effort,. communication skills, or rigid worldview

    • @mesaplayer9636
      @mesaplayer9636 2 ปีที่แล้ว +2

      I think he meant you were asking if you can leave constants in the equation without absorbing them into +C

  • @sayantansaharoy6349
    @sayantansaharoy6349 2 ปีที่แล้ว +126

    I love his attitude, man knows math and is happy about teaching it. I wish all my teachers were like him.

  • @aaronpahler5410
    @aaronpahler5410 2 ปีที่แล้ว +75

    As a physic student I can say, this is really lifechnaging, hours of pain will be joy instead. Thanks 🙏🏼

  • @MrTomas7777
    @MrTomas7777 2 ปีที่แล้ว +114

    Wow, such a simple idea that's hidden in plain sight! Just in time for my calculus test this week.

    • @Cjendjsidj
      @Cjendjsidj 2 ปีที่แล้ว +5

      Good luck for your exam bro.

  • @emoney1uz
    @emoney1uz 2 ปีที่แล้ว +67

    blessed to have him as my differential equations professor, couldn’t be luckier

    • @drpeyam
      @drpeyam  2 ปีที่แล้ว +25

      Awwwww thank you ❤️ It’s symmetric!

  • @MuPrimeMath
    @MuPrimeMath 2 ปีที่แล้ว +44

    How have I never seen this before? This is amazing!

    • @drpeyam
      @drpeyam  2 ปีที่แล้ว +7

      Omg hi Mu Prime Math !!!

  • @kobethebeefinmathworld953
    @kobethebeefinmathworld953 2 ปีที่แล้ว +397

    The fact is (even if we just think up to calculus level): whenever we do antiderivates, 99% of the time we forget the "+C", and this "+C" is the reason why we can end up with different answers depending on how we choose. Moreover, this also shows that the operation of antiderivate is not even a function as we can pick anything in the codomain for C as we want. So as long as the "number" that we "need" belongs to the codomain we can add it freely.

    • @gabrielmello3293
      @gabrielmello3293 2 ปีที่แล้ว +10

      Well, it is a function if you consider an equivalence relation between functions that differ by a constant.

    • @gabrielmello3293
      @gabrielmello3293 2 ปีที่แล้ว +5

      (And then it is a linear isomorphism)

    • @Cyrusislikeawsome
      @Cyrusislikeawsome 2 ปีที่แล้ว +3

      👆 put differently, Give it a couple years and you'll stop thinking of constants as really making them "different"

  • @pawebielinski4903
    @pawebielinski4903 5 หลายเดือนก่อน +2

    Wow, I expected this to be exaggerated, but it's actually really cool

  • @vrtxactivewear7383
    @vrtxactivewear7383 2 ปีที่แล้ว +17

    I've learnt the +1 -1 trick. on integration but this takes it to a new level - can't thank you enough!

  • @stevehof
    @stevehof 2 ปีที่แล้ว +12

    This blew my mind! So fascinating. I guess that's why in my courses it usually says "find the most 'general' antiderivative."

  • @violintegral
    @violintegral 2 ปีที่แล้ว +137

    This is one of the reasons why integration by parts is my favorite (and in my opinion, the most powerful) integration technique. Here's a really great (and difficult) integral for anyone interested: ∫√(1+x+x²)/(1+x)dx. Keep IBP in mind!

    • @davida2810
      @davida2810 2 ปีที่แล้ว +9

      int (1+x+x^2)/(1+x) dx = int 1 + x^2/(1+x) dx, then use u = 1+x.

    • @violintegral
      @violintegral 2 ปีที่แล้ว +7

      @@davida2810 no, that's the wrong function. (1+x+x²) should be under a square root. So the function was √(1+x+x²)/(1+x), which is much more difficult to integrate. Of course I wouldn't ask such a simple question that doesn't even involve IBP on a video about IBP.

    • @Vladimir_Pavlov
      @Vladimir_Pavlov 2 ปีที่แล้ว

      It is unlikely that integration in parts will lead to a result in this case.
      t=x+1 .
      ∫√(1+x+x^2)*dx/(1+x) =∫√(t^2 -t+1)dt/t=∫(t^2 -t+1)*dt/t*√(t^2 - t+1)=
      =(1/2)∫(2t-1)dt/√(t^2 -t+1)-(1/2)∫dt/√(t^2 -t+1)+∫dt/t*√(t^2 -t+1)=(*)
      In the last integral, replacing t=1/z leads it to an integral similar to the second.
      (*)=∫d(√(t^2 -t+1)) - (1/2)∫dt/√[(t-1/2)^2 +3/4] - ∫dz/√[(z-1/2)^2 +3/4]=
      =√(t^2 - t+1) - (1/2)* ln[t-1/2 +√t^2- t+1]- ln[z-1/2+√z^2-z+1]+C=
      = √(1+x+x^2) - (1/2)*ln[x+1/2 +√(1+x+x^2)]-ln[1/t-1/2+√(1/t)^2-(1/t)+1]+C=
      = √(1+x+x^2) - (1/2)*ln[x+1/2 +√(1+x+x^2)] - ln[(1-x)/2 +√(1+x+x^2)]+ ln|x+1|+C.
      (I use the equality ∫dt/√(t^2+λ)= ln|t+√(t^2+λ) |+C,
      a "long logarithm", and not a little informative expression through asinh).

    • @violintegral
      @violintegral 2 ปีที่แล้ว +1

      @@Vladimir_Pavlov actually, after substituting 1/y=x+1, you can perform integration by parts with u=√(y²-y+1), dv=-1/y²dy. You actually did the same substitution (in two steps), but used a different method after that. Anyway, it's nice to see an alternate solution to mine. Reciprocal substitutions can be very powerful, along with ibp!

    • @48_subhambanerjee22
      @48_subhambanerjee22 2 ปีที่แล้ว

      @@violintegral noicely done bro ... Yep we can use substitution.. but don't forget dy 😉

  • @GurpreetSingh-bg4jt
    @GurpreetSingh-bg4jt หลายเดือนก่อน

    I can't express how glad I am after getting to know this trick as an Aspiring Engineer ! Thank you Dr Peyam

  • @skylardeslypere9909
    @skylardeslypere9909 2 ปีที่แล้ว +558

    To be fair, the integral of x²/(1+x²) is relatively easy because that's just (1+x²)/(1+x²) - 1/(x²+1) which gives x - arctanx
    But nonetheless, this is a really useful trick I've never thought about. Nice video

    • @sergioconfero6049
      @sergioconfero6049 2 ปีที่แล้ว +9

      Yeah I ve thought the same thing

    • @tonyhaddad1394
      @tonyhaddad1394 2 ปีที่แล้ว +2

      Me 2

    • @user-th3tg4fb5g
      @user-th3tg4fb5g 2 ปีที่แล้ว +4

      yeah i agree but this does seem to be a nice tip

    • @annaclarafenyo8185
      @annaclarafenyo8185 2 ปีที่แล้ว +24

      Nope. The 'trick' only works in cases where the algebraic simplification also works. This is not a method, it is nothing.

    • @Cyrusislikeawsome
      @Cyrusislikeawsome 2 ปีที่แล้ว +11

      @@annaclarafenyo8185 the situations where OP's method work are precisely the situations in which Peyam's work. They're the same thing, just hidden behind algebra, like when an FB videos says to "take a number, double it, add one, half it, take away half the original number and boom you get 1/2 every time, spooky, right?"

  • @Unchained_Alice
    @Unchained_Alice 2 ปีที่แล้ว +8

    I never even considered this. Makes it so much easier!

  • @sooryanarayana3929
    @sooryanarayana3929 2 ปีที่แล้ว +13

    This trick is amazingly amazing, this really changed my life and how I see Integrals, thank you Dr. Peyam!

  • @antoniomacaione203
    @antoniomacaione203 2 ปีที่แล้ว +2

    It s amazing how something so important and so simple ,isn't used often

  • @ldc0322
    @ldc0322 2 ปีที่แล้ว +7

    I’m in my first year in college studying physics AND OH MY GOD I’M SO HAPPY I FOUND THIS BEFORE MY ANALYSIS EXAM

  • @syedzainulabidin5498
    @syedzainulabidin5498 10 หลายเดือนก่อน +4

    Mann that boom boom 3:01 !!! was so energetic 😅🎉

  • @sankalpranjan1863
    @sankalpranjan1863 2 ปีที่แล้ว +8

    Wow. As a math lover, I've fallen in love with this constant addition trick. As if, it was always there but we didn't see it ! Thanks a lot ❤️❤️❤️❤️

  • @РођакНенад
    @РођакНенад 2 ปีที่แล้ว +3

    My lord, such a simple yet elegant trick and it's so convenient.
    Many thanks for sharing it with us!

  • @8896tim
    @8896tim 2 ปีที่แล้ว +25

    For the ln(x+2)dx integral, you can substitute u=x+2 as well to bring it to a standard form

    • @Panda_2397
      @Panda_2397 2 ปีที่แล้ว +2

      He is using the same method but not showing you the substitution. d(x+C) where C is a constant

    • @carultch
      @carultch 9 หลายเดือนก่อน

      Here's an example with ln(), that is more interesting.
      integral ln(|x^2 - 4|) dx

  • @faenzarfaenzar2636
    @faenzarfaenzar2636 2 ปีที่แล้ว +1

    This is a God like power for integration !

  • @tomctutor
    @tomctutor 2 ปีที่แล้ว +42

    Never thought of doing that, gonna call it the "Peyam Integration Method"
    Something quite related of course is shifting the function,
    so; ∫ f(x+c)dx = ∫ f(u)du letting u= x+c.
    Ex: consider ∫ x/(x+1)dx
    ➙ ∫ (u-1)/u du with u= x+1, gives ∫ (1-1/u)du = u- lnu = (x+1)-ln(x+1)+const.
    Be careful though to change limits in definite form,
    so ∫ f(x+c)dx between x=a to b ➙ ∫ f(u)du between a+c to b+c

    • @drpeyam
      @drpeyam  2 ปีที่แล้ว +13

      Yep this would also make the ln(x+2) integral easier too

    • @tomctutor
      @tomctutor 2 ปีที่แล้ว

      @@robertveith6383 The area under 1.x yes, but simply ln(x) for integral, thats what Wolfram Alpha says anyhow.

    • @timothyaugustine7093
      @timothyaugustine7093 2 ปีที่แล้ว +1

      It's inspired from Ross's analysis book.

    • @coerciasink
      @coerciasink 8 หลายเดือนก่อน

      isn't that just substitution?

    • @tomctutor
      @tomctutor 8 หลายเดือนก่อน

      @@coerciasink Indeed but works in general for any function f(x+c) -> f(u)

  • @alaraf109
    @alaraf109 2 ปีที่แล้ว +1

    Just impressed!!!
    I have learned to integrate ln(x), arcsin(x) etc and looking for arctan(x)...... And found your method!!!
    Can't express how happy I have become!!! 😁😁

  • @turvivajpayee8947
    @turvivajpayee8947 2 ปีที่แล้ว +7

    Just can't explain how grateful I am to you for explaining this miraculously magical method
    Thanks alot ❤️

  • @zackwhite6199
    @zackwhite6199 2 ปีที่แล้ว +2

    This video truly lives up to its title.

  • @Handelsbilanzdefizit
    @Handelsbilanzdefizit 2 ปีที่แล้ว +18

    Very good, and very informative.
    Integral of ln(x+c) is easy, by integrating the inverse y = e^x - c, and subtract from the total rectangle area (x+c)ln(x+c). So, in your case: (x+2)ln(x+2) - x + c
    But don't forget to substitude the intervall endpoints. That's how I did it for years ^^

    • @tomctutor
      @tomctutor 2 ปีที่แล้ว +6

      That's Laisant' method, quite smart really. Problem is you may not have the actual inverse function to work with (logs are easy of course) but what about 1/(x^3+x+1)?

  • @shourya9998
    @shourya9998 5 หลายเดือนก่อน +1

    This video came in my feed many times, glad I finally watched it.
    Love you Dr peyam!

    • @drpeyam
      @drpeyam  5 หลายเดือนก่อน

      Thank you!!!!

  • @uncertainukelele
    @uncertainukelele 2 ปีที่แล้ว +26

    Me: has used integration by parts for years.
    Also me: never thought to use an antiderivative other than the C=0 version.
    Thank you for teaching me 😁

  • @thesnakednake
    @thesnakednake 2 ปีที่แล้ว +1

    Who knew adding one could be so revolutionary

  • @LotkroMath-zy4me
    @LotkroMath-zy4me 5 หลายเดือนก่อน +20

    This feels illegal

  • @omingnus
    @omingnus 2 ปีที่แล้ว +2

    Wow. Genuinely impressive.

  • @cody5535
    @cody5535 2 ปีที่แล้ว +6

    Absolutely stellar expedient method!

  • @_schnelli4800
    @_schnelli4800 7 หลายเดือนก่อน

    Can't believe this is my first time hearing this trick despite how obvious it is, will definitely look to apply it from now on.

  • @imperiumgraecum9126
    @imperiumgraecum9126 2 ปีที่แล้ว +13

    this is some serious math hack territory we are treading in

  • @thekingdragon6660
    @thekingdragon6660 6 หลายเดือนก่อน

    That is mind blowing, I used it on my math test and the integral went so smooth, thanks from the deepest part of my heart

    • @drpeyam
      @drpeyam  6 หลายเดือนก่อน

      Omg so glad it was useful!!

  • @kai_enforcer
    @kai_enforcer 2 ปีที่แล้ว +20

    I don't know why, but this makes me really happy 🤤🤗🖤🖤

  • @yu6879ehng9005yu
    @yu6879ehng9005yu 2 ปีที่แล้ว

    OHH GODD! I HAVE BEEN TRANSFORMED AND WILL NEVER LOOK AT ANY INTEGRAL THE SAME WAY AS I DID EARLIER!!!
    This is just ingenious and astoundingly simply, yet so effective!

  • @silentintegrals9104
    @silentintegrals9104 2 ปีที่แล้ว +5

    Solving integrals is allways fun!!!

  • @julianmoody5939
    @julianmoody5939 2 ปีที่แล้ว

    This video was recommended to me at midnight the day of my advanced integration unit test which is basically just a bunch of integration by parts and partial fractions. I’m both grateful and very concerned that youtube recommended me this

  • @yogeshwagh2849
    @yogeshwagh2849 2 ปีที่แล้ว +4

    Life changing man, for real 💯

  • @yoroida
    @yoroida 2 ปีที่แล้ว +2

    You're the man!! Usually it takes more than one videos to get me to subscribe.

  • @nedmerrill5705
    @nedmerrill5705 2 ปีที่แล้ว +5

    Truly exciting and imaginative!

  • @Cynic370
    @Cynic370 6 หลายเดือนก่อน

    Holy cheeze!, yesterday I was struggling with this integral, and I crunched it so many times without getting any easier expresion... And the answer was just there!

  • @egillandersson1780
    @egillandersson1780 2 ปีที่แล้ว +3

    What an amazing trick !!!
    Thank you for sharing.

  • @Jack_Callcott_AU
    @Jack_Callcott_AU 2 ปีที่แล้ว

    @Dr Peyam What a shock...a pleasant shock. Integration by parts will never be the same again for me

  • @aayushprasad7318
    @aayushprasad7318 8 หลายเดือนก่อน +3

    Being a JEE aspirant , its a very normal technique taught to us. However, its really nice of you to educate people so passionately.

  • @jusinocasino11
    @jusinocasino11 7 หลายเดือนก่อน

    Waiiiittt why haven't anyone thought of this, It's simple yet genius. Thank you so much Dr Peyam

  • @TheZanzaroni
    @TheZanzaroni 2 ปีที่แล้ว +3

    From my (limited) experience in math, if you just add and subtract that constant divided by the denominator in each case you should end up with the same result, still pretty fun though

    • @timothyaugustine7093
      @timothyaugustine7093 2 ปีที่แล้ว

      Yes, by adding a zero, you can obtain the same result as the trick although you might need to do a couple more steps.

  • @lia-rh7qj
    @lia-rh7qj 2 ปีที่แล้ว +1

    i absolutely despise by parts, but this changed my life! thanks!

  • @pandugus1550
    @pandugus1550 2 ปีที่แล้ว +5

    5:13
    My favorite part of this video 😎

  • @FlummoxTheMagnificent
    @FlummoxTheMagnificent 8 หลายเดือนก่อน +1

    That was actually incredible.

  • @MarcusCactus
    @MarcusCactus 2 ปีที่แล้ว +19

    At 0:50 he says "you start to cry necause this is very hard!"
    Well, not really... x² ÷ (x² + 1) is easily written as
    1 - 1 ÷ (x² + 1)
    which integrates immediately to x - arctan x.

  • @slavinojunepri7648
    @slavinojunepri7648 ปีที่แล้ว +1

    Beautiful tricks never cross one's mind until someone with enough insights reveal them. Thank you Dr. Peyam!

  • @stevewhisnant
    @stevewhisnant 2 ปีที่แล้ว +45

    Does this work with the D-I method of integration where you might have several levels of differentiation and integration? Here, if we are permitted to add an integration constant at each stage, we can build up a polynomial if required. That would be really cool and could really simplify some nasty integrals.

    • @ЕгорКут
      @ЕгорКут 2 ปีที่แล้ว +10

      Why not? Any antiderivative is equally legit, isn't it?

    • @drpeyam
      @drpeyam  2 ปีที่แล้ว +46

      Of course! When you choose the antiderivative in DI, just pick the right constant

    • @anupghimire4627
      @anupghimire4627 2 ปีที่แล้ว

      @@drpeyam yah

    • @carultch
      @carultch 9 หลายเดือนก่อน

      It can work, but it generally helps you the most on the regrouper types of integrals that you usually can do in just one row.

  • @paulregener7016
    @paulregener7016 3 หลายเดือนก่อน

    This video had so much charisma, I can’t believe it. Made me lol at the relax comment!

    • @drpeyam
      @drpeyam  3 หลายเดือนก่อน +1

      Glad you enjoyed it!

    • @paulregener7016
      @paulregener7016 29 วันที่ผ่านมา

      @@drpeyamAlright I made it to Calc 2 and my god this trick is hilarious my brain wants to think this way but years of schooling makes me doubt thinking like this.

  • @mudkip_btw
    @mudkip_btw 2 ปีที่แล้ว +6

    Very nice trick! It's always easy to forget the simple things if you're doing hard problems. This might save me half an hour sometime in the future :D

  • @jeeaspirant2232
    @jeeaspirant2232 8 หลายเดือนก่อน +1

    I am from now onwards love C's a lot ❤

  • @surajjani4868
    @surajjani4868 2 ปีที่แล้ว +4

    This is so awesome!

  • @Kabiiraaa
    @Kabiiraaa 7 หลายเดือนก่อน +1

    Thank you so much 😊

  • @jose6183
    @jose6183 2 ปีที่แล้ว +6

    I can't believe my eyes. Why didnt we know this before?

  • @hornet1904
    @hornet1904 8 หลายเดือนก่อน

    Truly life-changing. Was absolutely mind-blown

  • @michaelgolub2019
    @michaelgolub2019 2 ปีที่แล้ว +3

    Have never seen the method before... Really cool! I also remember than some functions (Ln, Arctan) are the same in the complex domain. It would be interesting to see similar simplification methods based on moving to the complex domain.

    • @carultch
      @carultch ปีที่แล้ว

      Another method is to simply add zero in a fancy way, to reconcile the fraction within the integral.
      Starting with:
      x^2/2*arctan(x) - 1/2*integral x^2/(x^2 + 1) dx
      Add zero in a fancy way, to the numerator of the integral, by both adding 1 and subtracting 1:
      integral x^2/(x^2 + 1) dx = integral (x^2 + 1 - 1)/(x^2 + 1) dx
      Regroup:
      integral [(x^2+1)/(x^2 + 1) - 1/(x^2 + 1)] dx
      integral [ 1 - 1/(x^2 + 1)] dx = x - arctan(x)
      Combine with the original expression:
      x^2/2 * arctan(x) - 1/2*(x - arctan(x))
      And simplify:
      (x^2 + 1)/2 * arctan(x) - 1/2*x

  • @sk3105
    @sk3105 8 หลายเดือนก่อน

    nahhh this is actually insane..my life feels like a lie for putting so much effort and not learning this earlier..thanks a ton for this

  • @_wetmath_
    @_wetmath_ 2 ปีที่แล้ว +8

    this trick is pretty cool, but after trying this in all my integration by parts questions, i can tell you that this trick only works for certain integrals and it's not something you should look out for all the time. just keep this trick in mind if you can cancel your antiderivative with a denominator later on

    • @uwuifyingransomware
      @uwuifyingransomware 2 ปีที่แล้ว +1

      How do you figure out which integrals it does/doesn’t work for?

    • @Cjendjsidj
      @Cjendjsidj 2 ปีที่แล้ว

      @@uwuifyingransomware im guessing by practice

    • @_wetmath_
      @_wetmath_ 2 ปีที่แล้ว

      @@Cjendjsidj yeah by practice. it's not worth it to intentionally leave a gap and write (x+_). i suggest using this trick only when you are stuck or happen to notice the perfect setup for this trick

    • @timothyaugustine7093
      @timothyaugustine7093 2 ปีที่แล้ว

      @@uwuifyingransomware You'll figure it out by experience after dealing with a bunch of different functions in many integration problems. You must have substantial experience in functional analysis and how to manipulate those functions using several derived formula which will help simplify the problem. You may not be able to solve all integrals since not all integrals can be solved but most can be solved using the normal techniques you've learned i.e. elementary functions, algebraic/trigonometric/hyperbolic substitutions, powers of trigonometric/hyperbolic functions, recurrence relations, partial fraction decomposition for rational functions and of course, integration by parts.

  • @zombiefelice
    @zombiefelice 2 ปีที่แล้ว

    Im almost crying how good this is , Thank you very much for sharing

  • @SelvaKumar-th1lh
    @SelvaKumar-th1lh 2 ปีที่แล้ว +23

    I don't even know integration 😂

    • @sebastiangudino9377
      @sebastiangudino9377 4 หลายเดือนก่อน

      There are two basic techniques which are pretty easy to understand in isolation. One is integration by parts (Multiple interations of it are done with the tabular method, or DI method) the other is U-Substitution, which is like anti-chain rule. You learn those two bad boys, and if you are good with algebra and can also think geometrically, then you have a solid foundation to learn calc I-II ideas

  • @misterdubity3073
    @misterdubity3073 2 ปีที่แล้ว +1

    Wow!! I did not see that coming. Very powerful trick. And I like the "marker toss" at the end. "Marker drop" will be the new "mic drop". Subscribing now.

  • @mohammedal-haddad2652
    @mohammedal-haddad2652 2 ปีที่แล้ว +5

    Dr. Peyam: Thanks for watching.
    Me: Thanks for changing my life!

  • @chrstfer2452
    @chrstfer2452 2 ปีที่แล้ว +2

    Yeah that is pretty awesome. I definitely remember being taught this now that you mention it, but i didnt come up with it when i did the example so thanks for the reinforcement!

  • @AdityaKumar-gv4dj
    @AdityaKumar-gv4dj 2 ปีที่แล้ว +5

    0:01 "Thanks for Watching". 😂😂

  • @Shubhyduby
    @Shubhyduby 4 หลายเดือนก่อน +1

    Incredible. Thank you so much for this trick!

  • @gunhasirac
    @gunhasirac 2 ปีที่แล้ว +3

    TBH without adding the constant term in the first place, I will still tackle the second term by adding 1 to the numerator which gives the same result with one more line, but this method is definitely more efficient and some thing I should keep in mind. Thx
    Btw second one I will do with change of variable, same as third, but third one still need a constant to do neatly, so very clever examples for showing the power it does.

  • @fantiscious
    @fantiscious ปีที่แล้ว +2

    0:46 I use an add-and-subtract method here;
    (x²)/(x²+1) = (x² + 1 - 1)/(x² + 1) = (x² + 1)/(x² + 1) - 1/(x² + 1) = 1 - 1/(x² + 1); this becomes much easier to integrate
    It's just like doing polynomial long division, except you don't cry while dividing

  • @rarebeeph1783
    @rarebeeph1783 2 ปีที่แล้ว +4

    so basically, this is taking the "integral(udv) = uv - integral(vdu)" and expanding it without loss of generality to "integral(udv) = u(v+C) - integral((v+C)du)"

    • @drpeyam
      @drpeyam  2 ปีที่แล้ว +2

      Precisely!!

  • @asadyezdan3858
    @asadyezdan3858 ปีที่แล้ว

    This is unbelievably gorgeous

  • @Convergant
    @Convergant 2 ปีที่แล้ว +3

    This is some omega brain shit lmao

  • @astonallsopp5746
    @astonallsopp5746 2 ปีที่แล้ว

    I love his enthusiasm

  • @bishakhaalva800
    @bishakhaalva800 8 หลายเดือนก่อน +10

    Who's here for CBSE class 12th boards 2024?

    • @umersiddiqui-c4r
      @umersiddiqui-c4r 8 หลายเดือนก่อน +2

      broooo me after struggling from integration

  • @pain8117
    @pain8117 2 ปีที่แล้ว

    I have no idea how this ended up in my recommended feed, but THANK GOD IT DID

  • @zeddyknight2478
    @zeddyknight2478 2 ปีที่แล้ว

    I found this when I’ve been suffering the most with Calc 2 thank you kind sir

  • @chromiyum6849
    @chromiyum6849 2 ปีที่แล้ว +1

    Totally blown my mind! Shared to all my calc homies

  • @abrahamelnikety151
    @abrahamelnikety151 2 ปีที่แล้ว +1

    I literally have a calculus 2 exam tomorrow, this makes it so much easier

  • @246Trinitrotoluene_
    @246Trinitrotoluene_ 8 หลายเดือนก่อน

    This is gonna change my life forever!!

  • @harjotkaur4818
    @harjotkaur4818 2 ปีที่แล้ว +1

    a neat concept that clarifies the +c as well👍👍👍

  • @hoveruler8722
    @hoveruler8722 7 หลายเดือนก่อน +1

    the best method is DI method where we make a small table and write d and i on top which refers to differentiation and integration. then chose the first function and second function and the first function is always differentiate so keep the first function on the D column and the second on I column. suppose we take x^2 and sinx and x^2 i put it in D column and sinx in I. now simply keep on differentiating till you get zero in first column and keep on integrating the second . now change the signs alternatively on D column (start with + then go with - and then + and so on)anddd cross multiply from D column and VOILA YOU GOT IT :)

  • @lifeofsahani
    @lifeofsahani 2 ปีที่แล้ว +1

    This is truly life changing!!!

  • @mathperson6927
    @mathperson6927 2 ปีที่แล้ว +1

    This sort of reminds me of 7th grade, when we learned about "completing the square."
    This trick is really smart and I will use it in the coming years. Thank you :)

  • @kooklatte
    @kooklatte 6 หลายเดือนก่อน

    I JUST CANT THANK YOU ENOUGH FOR THIS!!!!!

    • @drpeyam
      @drpeyam  6 หลายเดือนก่อน +1

      You’re welcome!!!

  • @yessirmate8357
    @yessirmate8357 2 ปีที่แล้ว

    this would’ve been helpful last semester. thanks, youtube recommended.

  • @sonalisharma8416
    @sonalisharma8416 2 ปีที่แล้ว +1

    You are so positive 💜

  • @DeLuini985
    @DeLuini985 8 หลายเดือนก่อน

    Wow, just wow.
    This is like an unfair advantage that's fair. Thanks dr.Peyam