❖ U-Substitution - More Complicated Examples ❖

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  • Опубликовано: 27 окт 2024

Комментарии • 591

  • @tms1266
    @tms1266 3 года назад +40

    Excellent explanation.
    There was a little mistake. For the third problem, the denominator has + between (1-x^2) and sqrt(1-x^2). That being said, you would need change the minus sign in your denominator between u and square root of you, v^2 and v, and finally between square root of (1-x^2) and 1 at the ending result.

  • @MrTom510513
    @MrTom510513 10 лет назад +166

    u made a mistake on 4:37- 4:41. It should be a "+" sign

    • @Nithesh2002
      @Nithesh2002 7 лет назад +6

      chan tom thanks, I thought I messed up hahah

    • @mannyramirez8265
      @mannyramirez8265 7 лет назад +1

      Nithesh S. he factored out a negative, thus changing the inside functions polarity

    • @gaurav.raj.mishra
      @gaurav.raj.mishra 7 лет назад +18

      Manny Ramirez Nope

    • @mikekato7761
      @mikekato7761 6 лет назад +5

      Sure he messed up

    • @henryjiang9664
      @henryjiang9664 6 лет назад +8

      Mike Kato The solution should be -ln|sqrt(1-x^2)+1|) + c

  • @tncreations1267
    @tncreations1267 11 месяцев назад +6

    Just letting you know that your video is still helping people to get through calculus. Thank you very much.

  • @fluffybasket5674
    @fluffybasket5674 10 лет назад +275

    Can you please replace my calculus professor?

    • @agil-j4n
      @agil-j4n 6 лет назад

      mine too

    • @Corentinbes
      @Corentinbes 5 лет назад +11

      Calculus professor substitution

    • @MG-hi9sh
      @MG-hi9sh 5 лет назад

      Mac Just watch his videos instead man. Bin your professor.

    • @Infinitesap
      @Infinitesap 4 года назад +1

      Don't you mean SUBSTITUTE? :)

  • @thatguyoverthere54
    @thatguyoverthere54 9 лет назад +50

    7 years later, and this video still helps Calculus students like me :)

    • @philwesom8784
      @philwesom8784 6 лет назад +5

      10 years bro...

    • @Xx-bz4gy
      @Xx-bz4gy 5 лет назад +2

      11 years man...

    • @1_adityasingh
      @1_adityasingh 4 года назад +1

      17 years man...

    • @offshock1587
      @offshock1587 4 года назад +1

      @@1_adityasingh :D this was made when I was born, and waited for me to click on it my entire life, I guess

    • @djalalmaster1018
      @djalalmaster1018 2 года назад +1

      13 years

  • @seizureboy999
    @seizureboy999 9 лет назад +139

    your v's look like square roots :(

  • @haruharu380
    @haruharu380 4 года назад +1

    12 years and counting but bruh u're still helping a lot of students who are unfortunate on math teachers sskksks hope you're earning what's right for you now.

  • @AfroQueenB
    @AfroQueenB 13 лет назад +1

    at the beginning of the day i couldn't be able to explain what U-substitution even had to do with anything but after watching all of patricks U-Substitution videos I've learned more than my teacher or my stupid calc book could ever teach me. Kudos from MA.

  • @CodyBalos
    @CodyBalos 9 лет назад +12

    It'd be pretty cool if in videos where all you are doing is examples, you showed a preview of each type of problem you will do with links to the time that you do each example. It might not be worth the effort, but just a thought! Thanks for all your videos, they have helped me go from a B math student to 94% in Calc I!

    • @patrickjmt
      @patrickjmt  9 лет назад +7

      +Cody Balos that is a good idea, i will keep this in mind for future videos

  • @zahranaseri4759
    @zahranaseri4759 10 лет назад +3

    Many Thanxx, you're my hero. I don't know why my lecturer couldn't teach it as clear as you.

  • @jonnyd6087
    @jonnyd6087 Год назад

    I love your little comments catering to the people LEARNING. One of my biggest problems with some professors is they seem to not address or display any understanding or acknowledging the difficulty something might have for people who are LEARNING. Your comments show you are a very good teacher by acknowledging that "when you don't know how to do something, sometimes it seems like the hardest thing ever".

  • @acoti
    @acoti 15 лет назад +1

    I never would have thought to do a double substitution. Your work is amazing and I've been watching your Integration videos for a few days now and they're helping me so much! Thank you for these videos.

  • @chococookies1435
    @chococookies1435 10 лет назад +3

    Sometimes I feel like you are a magical mystical being that just KNOWS.
    Thanks for being awesome!

  • @shintaayam
    @shintaayam 8 лет назад +4

    How could i just found your channel!!?? You teach so good, better than my math teacher

    • @magnusrobinson8735
      @magnusrobinson8735 8 лет назад +1

      +Eat, Love and Eat Again Welcome to the good life! :-)

  • @CHAPPYx12
    @CHAPPYx12 13 лет назад +1

    Thank you soo much for these videos. My teacher shows us the easiest example and then expects us to learn the rest on our own, you pretty much are my Calculus teacher, thanks, you rock!

  • @patrickjmt
    @patrickjmt  13 лет назад

    @AhOhy sorry, i do not do hw questions - it could be stuff for a grade and i am not comfortable answering that. however, i will give you a hint: you picked the wrong u sub.

  • @patrickjmt
    @patrickjmt  14 лет назад

    @cincottallll so teach yourself if you are that interested in it! why wait for someone to 'teach' you? although you need some trig as well before you jump into it.

  • @patrickjmt
    @patrickjmt  13 лет назад +1

    @vhskeva ha! glad you like the videos so much : ) sometimes i turn on like 15 videos at once and get a surreal patrickjmt effect. my wife thinks i am crazy ( i also do it to annoy her!!)

  • @colliefarm570
    @colliefarm570 2 года назад +1

    Once again, thank you for these videos which are concise, explain the theory AND how to do it (the algebra part). My calc I teacher does his best to explain these things but it doesnt make sense. I've been using your videos since last summer's Trig class with him and now for Calc I (my husband used your videos as well when he was in school and is the one who suggested you). What a BLESSING! Your videos are the main reason Im grasping the concepts and how to do the problems. And with finals coming up in 8 days, theyre helping me learn and review everything as well! See ya in Calc II. thanks again!

  • @zzypingan
    @zzypingan 16 лет назад

    great video very clear! just to mention that to others who is watching this video, the question involving 2 substitutions does not necesserily need 2 subs, u^2=1-x^2 gives same answer.

  • @lailamahmudah5217
    @lailamahmudah5217 6 лет назад

    10 years later and I still find this video useful. Thank you Sensei

  • @patrickjmt
    @patrickjmt  16 лет назад +2

    the first integral can not be integrated.
    you would use a series expansion to approximate it to any desired amount of accuracy however.
    the second integral is just arctan(x).
    for the third, i assume you mean:
    1/[x(4x+1)^1/2]
    at a glance like you would let u = (4x+1)^1/2
    solve for x, find dx, plug it all in and you would have a problem that you would have to use partial fractions on

  • @patrickjmt
    @patrickjmt  14 лет назад

    @sam1209 sometimes it is nice to take the scenic route.

  • @ganendrav
    @ganendrav 8 лет назад +26

    hi patrick, at 4:46 u wrote u - sqrt(u) . it should be +
    small error but great video nonetheless. thank you!

  • @patrickjmt
    @patrickjmt  13 лет назад

    @bobish101 so for x in your u = 16 + 2x part; then plug that in, divide it out and integrate

  • @GenaEnSamIAm
    @GenaEnSamIAm Год назад

    Today I am a what I'd like to call a successful engineer.
    Thank you Patrick.
    We all owe you.

  • @neodine
    @neodine 12 лет назад +1

    You and Sal really helped to pass all my uni math courses, big thanks to you!

    • @kapjoteh
      @kapjoteh 4 года назад

      This guy is better

  • @bluestaragar3976
    @bluestaragar3976 8 лет назад +1

    Night before Calc BC test feeling pretty great about it. This video reinforced my confidence. Thnx bro

  • @patrickjmt
    @patrickjmt  14 лет назад

    @bamf703 trying to keep the v's from lookin' like u's

  • @patrickjmt
    @patrickjmt  16 лет назад +3

    yes! you are absolutely correct! it should be u + u^5! thanks for pointing out the error!

  • @Phalanx73
    @Phalanx73 13 лет назад

    Thanks a lot:I have an exam tomorrow, I was absent when my class was doing substtitution techniques, I got a handout my teacher made on it so I can study but it was like bullshit...so, there I was looking for help on the internet, and found just the one! It was easy to understand I didnt need to re-watch it many times to grab the idea of it...too bad YOU arent my teacher!!!lol pls keep uploading!! thx.

  • @patrickjmt
    @patrickjmt  13 лет назад

    @ladyasphodel i prefer complicating things as much as possible.

  • @patrickjmt
    @patrickjmt  13 лет назад

    @JRaby21 u have to use taylor series. it does not have an elementary antiderivative

  • @davidrollins9229
    @davidrollins9229 8 лет назад +3

    For the last problem you can just set u to x+4 instead of (x+4)^(1/3)
    U=x+4
    X=u-4
    Du=dx
    Integrate (u-4)*u^(1/3) du
    To get the same answer... But a little simpler

  • @john121447
    @john121447 11 лет назад

    you have perfect handwritting , explanation skills as well as pace

  • @hanamcavoy6952
    @hanamcavoy6952 6 лет назад

    Finally understood this before 2 hours from the exam! Subscription well deserved sir

  • @patrickjmt
    @patrickjmt  16 лет назад

    yes, sorry about that! someone else pointed it out! i add text comments into the video so that people will now be aware of the mistake. Thanks for pointing it out!!!

  • @theson22788
    @theson22788 7 лет назад +12

    i find the hardest thing to do is double or triple substitution.i lost track of them quite a bit.

  • @TheUSASecret
    @TheUSASecret 8 лет назад +25

    I want you pens ... that is why people are good at math, sometimes they want to write with cool pen.

  • @patrickjmt
    @patrickjmt  16 лет назад

    yep! you are right

  • @Actraiser1
    @Actraiser1 9 лет назад +115

    That third example is satanic. Would never get that on a test :/

    • @ruskodudesko9679
      @ruskodudesko9679 8 лет назад +3

      Average? That's like you have to be able to do it in your head in my course - try ⌡√(tanx)dx

    • @rajatbansal512
      @rajatbansal512 8 лет назад

      What course are you talking +rusko dudesko

    • @ruskodudesko9679
      @ruskodudesko9679 8 лет назад +1

      Rajat Bansal calc 2

    • @rajatbansal512
      @rajatbansal512 8 лет назад

      *****​ k which university or college

    • @ruskodudesko9679
      @ruskodudesko9679 8 лет назад

      Rajat Bansal at a community college - I'm transferring to UCSC as a junior, here is a question I pulled from random on an exam:
      ⌡1/(2-sinx)dx
      and one I picked just to prove this guy wrong:
      ⌡(2x+1)/(x^4+x)dx

  • @odinheim
    @odinheim 14 лет назад

    Patrick we all thank you so much you made our math's struggle an easy task , without you we have not passed our exams
    thanks
    we should make a donation to support you for what you do without any financial interests
    we all love you
    long live the mathematics and the mathematicians

  • @patrickjmt
    @patrickjmt  13 лет назад

    @omegaplatypus cause i used to get them cofused with ' u ' so i put a little hook on them to help myself

  • @magnusrobinson8735
    @magnusrobinson8735 8 лет назад +2

    Hi Patrick, Regarding the third question. Why did you choose such a difficult U substitution? I used U=x+4 and it's much easier to follow. I don't mind the U sub used mainly because it showed me a different way of doing it but I found that more difficult. I'm just saying in case someone was thinking of doing the same I did. Thanks for all the help. You're pretty much a super hero to me!

    • @kyleairforce
      @kyleairforce 8 лет назад

      I did it the same way and got the same answer.

  • @chadwad12
    @chadwad12 12 лет назад

    I used to think this kind of math was just dumb to do. Then I found Patrick. Anytime I have a question about how to do something I immediately search your website and RUclips Channel. It immediately becomes clearer and a light bulb pops into my head. Now I almost look forward to moving into my higher level math classes at my university as I work towards my Computer Science degree.

  • @bmwbaby90
    @bmwbaby90 12 лет назад

    i love u patrick because of u i passed my calculus classes

  • @ultimatekenz
    @ultimatekenz Год назад

    14 years ago! thank you for posting this!

  • @JasonRobards2
    @JasonRobards2 12 лет назад

    Thanks Patrick, this video helped a lot. The problem at min 8 was just the one I was stuck at.

  • @patrickjmt
    @patrickjmt  13 лет назад

    @D4ntesword yes, that is wht i would do

  • @radaradaitsbob
    @radaradaitsbob 11 лет назад

    You teach way better than my teacher! Finally, something I can understand. Now I can ace the test I have tomorrow. :) Thank you for all your hard work~

  • @patrickjmt
    @patrickjmt  14 лет назад

    @mylesbianify well i assume you meant u-substitution. if he meant trig substitution, that is correct

  • @ftwi49
    @ftwi49 13 лет назад

    omg u saved my life!! my high school calc teacher is terrible and because of that my grade is falling, but with your video you totally saved my ass! thank you!!!

  • @edel1561
    @edel1561 12 лет назад +2

    OMG you are actually amazing! you are helping me with so much of my university work! i love you" you are a genius! and such a good teach! you explain things so well! :)

  • @IHeartViHart
    @IHeartViHart 12 лет назад

    Remember that terms inside square roots can be manipulated algebraically just like a normal fraction. In the same way that (5/x)/(x/5) = (5/x)*1/(x/5) = (5/x)*(5/x) = 25/x^2, sqrt(5/x)/sqrt(x/5) = sqrt(5/x)*sqrt(5/x) = 5/x. Taking the integral is simple from there.

  • @patrickjmt
    @patrickjmt  15 лет назад +1

    ya, you are wrong : )
    you can do a u substitution (let u = v+1) to change it to 1/u ------------- when you integrate that, you get ln(u) which is ln(v+1) in this case

  • @Team3DAlpha
    @Team3DAlpha 12 лет назад

    QUESTION around 05:08 i still don't understand why you had to square the square root of U. I'm confused as to why we can't write it as U to the one half and then differentiate. Sorry i haven't done calc in a while and i'm rusty as *$%^.

  • @djd259th
    @djd259th 14 лет назад

    ∫ ex
    haha! There was a small mistake at the conclusion of the ∫ x/(1-x^2)+sqrt(1-x^2). Patrick writes -ln | sqrt(u) - 1 + C, which causes him to mistake the the closing bracket of the absolute value sign for a # 1, so he gives the final answer (incorrectly) as -ln | sqrt(1-x^2 - 1 | + C, when in fact it should have been -ln | sqrt(1-x^2 | + C. I'm only bringing this up to avoid confusion, I'm so grateful for this video I would never ever post a negative comment. Thank you millions of times!

  • @akksay
    @akksay 8 лет назад

    You are the best mathematician I have ever known!

  • @MARTINREN1231
    @MARTINREN1231 10 лет назад +1

    this helped me in so many ways O: thank youuuuuuu(because what they discussed in school is far away from what is given to us in assignments and exams xD)

  • @patrickjmt
    @patrickjmt  14 лет назад

    @mylesbianify no, you can not. it looks like a trigonometric substitution to me (after completing the square)

  • @chucksneedmoreland
    @chucksneedmoreland 14 лет назад

    Everyone should stop complimenting patrick's teaching style, because then he might go and teach again.
    This dark prospect must not, cannot, will not happen! What would we do then?!?
    j/k
    Thanks for the help. Finally I get u-substitution.

  • @rockstar377
    @rockstar377 11 лет назад +1

    I'm failing my math class because my teacher can't explain how to do anything but you are saving me right now I think I will pass. Haha. thank you.

  • @habooshirahhal2581
    @habooshirahhal2581 9 лет назад +1

    Thank u soooo much for your videos!! You're such a great teacher I always recommend ur videos to my friends 😊 I really find them very useful and they have helped me a lot!! Thank u again!

  • @patrickjmt
    @patrickjmt  16 лет назад

    no problem!

  • @ommyskills8799
    @ommyskills8799 7 лет назад +1

    the best lecturer ever..now I like calcus coz of u.

  • @patrickjmt
    @patrickjmt  16 лет назад

    aw yea, no problem!

  • @daweriqbal7216
    @daweriqbal7216 5 лет назад +1

    2k19 and tomarrow is my calculus exam... THANKS BOI👍

  • @patrickjmt
    @patrickjmt  16 лет назад

    well, you can treat it as a fraction!
    plus, we are calculating the differential:
    the differential of u = e^x
    is du = e^x dx

  • @megaelliott
    @megaelliott 15 лет назад

    i see by your wide range of the english vocabulary, that you would do even better in an english exam

  • @FlippinPin0y
    @FlippinPin0y 15 лет назад

    The way you explain it is so clear and is can be easily understood, and the way you film it particularly helps too. Are you sniffing the marker? lol jk, thank you very much!

  • @MarkBies
    @MarkBies 15 лет назад

    Just take u to be 3x+2, this will result in
    1/3 du = dx meaning: you will get:
    1/3 * 8 outside and the inside of the integral will be 1/u which you can solve into ln(u)
    So it should be 8/3*ln(3x+2) + C

  • @HisBelovedQueen
    @HisBelovedQueen 9 лет назад +11

    second question: how did we know to use substitution the second time for v?

    • @HimalayanBat86
      @HimalayanBat86 8 лет назад

      +Apollo-milkchocolate If you have something that can be replaced and the integral could be reduced to something that will work out itself

  • @omegaplatypus
    @omegaplatypus 13 лет назад

    1. You're the hero Gotham deserves. You pretty much taught me calculus singlehandedly.
    2. WHY DO YOUR V'S LOOK SO MUCH LIKE RADICAL SYMBOLS???

  • @were455
    @were455 16 лет назад

    Hi man GREAT VIDEO!!!!!!! Just one small question. Take the first question for example you took u=e^x so du/dx=e^x, at 1.13 you wrote du=e^xdx. I just wanted to know how you can do that because I thought that du/dx was a symbol not a fraction. (Please get back to me) Once great video!!!!! Really clear and well explained THANKS!!!

  • @Rattattattatt
    @Rattattattatt 15 лет назад

    Alright. So not once have I looked up anything math related on youtube, but I love it and am going into electrical engineering, and this was under the "Recommended for you" tab. Kinda weird right?

  • @patrickjmt
    @patrickjmt  15 лет назад

    whats wrong with natural log? : )

  • @MrJrred299
    @MrJrred299 8 лет назад +1

    Great explanation...very comprehensive examples...Thanks

  • @jannyp.bonalan2061
    @jannyp.bonalan2061 Год назад

    There is something wrong in Final answer in Example 4 but thank you so much sir for this. You really explained very well and I really understand it also.

  • @numa1401
    @numa1401 8 лет назад +1

    Good examples with better explanation, get it boy......Thanks for the video..

  • @alhaithamaljabri2203
    @alhaithamaljabri2203 7 лет назад

    2017 and you rock all the time!

  • @abaundwal
    @abaundwal 8 лет назад

    At 7:44, why did you not put u=x+4 just because it was a cube root and not a square root?!! Nice videos, btw. They help me a lot!

  • @techienauty1689
    @techienauty1689 7 лет назад +1

    A tip:
    For last example even if it (x+4) raised to power of 1/3 or 1/2 you can just substitute x+4 as u. And enjoy.
    you will get same answer...Go try.

  • @KhaozOfTrouble18
    @KhaozOfTrouble18 12 лет назад

    I have a test about this today. This just made me understand everything! Thanks

  • @davidomer7890
    @davidomer7890 9 лет назад

    Simpler solution to the 3rd problem:We shall simplift the denominator: sqrt(1-x^2)[ sqrt(1-x^2)+1].Therefore:int(x dx/( sqrt(1-x^2)[sqrt(1-x^2)+1]Let's substitute u=sqrt(1-x^2)-----> du=-[x/sqrt(1-x^2)]dx.Conseqeuntly we simplified the given problem:-int(dt/(u+1)) Which is the linear case----> -ln|u+1|+c -----> -ln|sqrt(1-x^2)+1|+c

  • @anitajurjevic6255
    @anitajurjevic6255 10 лет назад +5

    You have made the last example way more complicated than it needs to be. x=u-4 as u=x+4 and du=dx. Make the substitutions and you still get the same answer but with half the working out.

    • @talkaboutphones4831
      @talkaboutphones4831 10 лет назад

      are you sure about that ( the answer should be) = (x+4)^3 /3 - 2(x+4)^2 + c
      i do not have calculator to chick that :/

    • @rhythmehta
      @rhythmehta 7 лет назад

      Yeah it works!

  • @patrickjmt
    @patrickjmt  13 лет назад

    @TrAnScEnD3nT derivative of e^x is e^x

  • @matthewstroud8938
    @matthewstroud8938 11 лет назад

    It is the chain rule. The derivative of ln sinx is 1/sinx times the derivative of sinx, which is cosx

  • @patrickjmt
    @patrickjmt  13 лет назад

    @patrickJMT solve for x that is

  • @Rob3P
    @Rob3P 12 лет назад

    The final expression simplifies further to 3u^4[u^3 / 7 - 1] + c = 3/7(x-3)(x+4)^(4/3) + c

  • @christianpatrickfernandez62
    @christianpatrickfernandez62 8 лет назад

    AWESOME VIDEO. You sir just saved me from alot of trouble. 👏🏻

  • @MsAgnosia
    @MsAgnosia 8 лет назад +2

    I usually have difficulty in figuring out whether to do substitution before integration by parts or after, is there any way that can help me understand it better? Also, thanks for all the videos, they are a life saver :) !

  • @thomasarch5952
    @thomasarch5952 5 лет назад

    Another way to approach this would be to let x = sin v and then you have dx = cos v dv and the integral would become
    (sin v cos v dv) / ((1 - (sin v)^2) + sort(1 - (sin v)^2) which would lead to the same correct answer.

  • @patrickjmt
    @patrickjmt  15 лет назад

    they do not care about comments on youtube. they care about grades on tests : )

  • @patrickjmt
    @patrickjmt  15 лет назад

    whys that? did i do something stupid in the vid or something? : )

  • @BYMYSYD
    @BYMYSYD 13 лет назад

    This was very helpful. Thanks Patrick.

  • @Baidyabati
    @Baidyabati 11 лет назад

    Well, in the third problem if you substitute sqRt (1-x^2) as "u", you can solve it faster, you won't be needing a second substitution.
    Integral -u/(u^2+u) = integral - 1/( u+1) = -ln (u+1) + C = -ln (sqrt[ (1-x^2) +1] +C

  • @karenroman290
    @karenroman290 10 лет назад +7

    -Question-
    In the third problem, first substitution, in the denominator, why did u put
    u - sqrt (u)
    If the original equation says
    (I - x^2) + sqrt (1 - x^2 )
    Shoudn't it be
    u + sqrt (u)

  • @anirbanmra
    @anirbanmra 8 лет назад +2

    I think that there is a slight arithmetic mistake there, u wrote - instead of plus.
    I substituted sq rt. (1-x^2) = u
    I think that solves the problem in an easy way without the second substitution.

    • @daudmohamed9672
      @daudmohamed9672 8 лет назад +1

      yeah i saw it also. could you make it clear please....

    • @SlowGreyWeasel
      @SlowGreyWeasel 6 лет назад

      i did the same thing and it's faster and easier to understand for me

  • @Makeanimagination
    @Makeanimagination 11 лет назад

    I like to clap every time whenever you solve a problem, by explaining it in a excellent way...

  • @calipdis2
    @calipdis2 15 лет назад +1

    XD is so weird how everything is simpler here, but in college is like odd, thank you very much