U-substitution with definite integral

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  • เผยแพร่เมื่อ 10 ม.ค. 2025

ความคิดเห็น • 94

  • @warwick802
    @warwick802 2 ปีที่แล้ว +11

    For calculus 2 you basically choose to either plug back "u" and leave the bounds alone or change the bounds and leave it as u.

  • @wtbgothgf
    @wtbgothgf 8 ปีที่แล้ว +4

    You have no idea how much you've helped me out this semester. I'll do my best to pay it forward!

  • @GatorsCloset
    @GatorsCloset 12 ปีที่แล้ว +3

    This video is more complicated than it needs to be. When you substitute the "1/2x" into the integral you'll have "x/2x" the x will disappear and you'll be left with "1/2" and since it is a multiplier you just bring the one half outside of the integral. This is a lot more simple than multiplying by two and one half to keep the integral the same in order to have a "2x/2x".

  • @gracepackard6838
    @gracepackard6838 8 ปีที่แล้ว +5

    Sal, you are the light of my life.

  • @HotPepperLala
    @HotPepperLala 12 ปีที่แล้ว +4

    Sal sounds so organized and prepared now. But for some reason I like the old Sal videos lol

  • @allieyi
    @allieyi 7 ปีที่แล้ว +5

    Thanks so much! I have test this morning, and I needed this!

  • @muffemod
    @muffemod 6 ปีที่แล้ว +11

    Warning: In order to use substitution, the intergrand must contain the derivative of the inside function, to within a constant factor.

    • @pram5532
      @pram5532 3 ปีที่แล้ว +3

      tf is an intergrand

    • @JasonVaysberg
      @JasonVaysberg 3 ปีที่แล้ว +5

      @@pram5532 the function that is going to be integrated. xsin(x^2) is the integrand in this case.

    • @NewWesternFront
      @NewWesternFront 2 ปีที่แล้ว +2

      @@pram5532 it's a form of ligma

    • @jonathanalonso6492
      @jonathanalonso6492 ปีที่แล้ว +1

      @@pram5532 An integrand is the result from basically converting an integral back into a higher-order function. An integral is the same as getting the derivative of whatever higher-order function you started off with. For example: an integral, like 2x, is what you get after differentiating x^2.
      They are opposites of each other.

  • @mikeymike343
    @mikeymike343 10 ปีที่แล้ว +17

    I love you Sal, you did in 5 minutes what my textbook did in 30.

  • @Heirophanteye
    @Heirophanteye 12 ปีที่แล้ว +1

    Sorry, I have a Masters in both Business Admin and Accounting. I took AP Calculus AB and BC in High School but didn't have to in college. I am always looking to improve myself so I am trying to learn new things; such as refreshment on calculus and physics topics.

  • @Thedreamshaperabc
    @Thedreamshaperabc 12 ปีที่แล้ว +1

    Well often this would be only a very small part of a larger application, not all things can by it self be directly applied. I truly get how we want things to have a direct application, but sometimes one simply needs to take a leap of faith and try to learn the theory and realize than unless one wants to go into plumbing and construction, some times things will get abstract :)

  • @DRJACOBB
    @DRJACOBB 12 ปีที่แล้ว

    I was an award winning teacher--in the fourth largest district in the United States, I harnessed the power of technology to take my students to places they have never been! I provided implementation ideas to my school and the children really benefitted. More power to you! By the way, "Giving Our Students the World" is my motto and it is now the motto for ~ 400,000 students. So, yes, I AM a caring teacher--that's my philosophy.

  • @joelplascencia3568
    @joelplascencia3568 8 ปีที่แล้ว +48

    You see, I understand how to do it now, but I still don't get the purpose.

    • @GrimmjowJaegerjaquez
      @GrimmjowJaegerjaquez 6 ปีที่แล้ว +25

      Joel Plascencia it's been two years, do you get the purpose yet?

    • @thebanish3r355
      @thebanish3r355 5 ปีที่แล้ว +1

      3?

    • @jamesrich3161
      @jamesrich3161 5 ปีที่แล้ว +3

      3 years later and your question still stands buddy

    • @mohammedhoque7671
      @mohammedhoque7671 4 ปีที่แล้ว +3

      4 years still no purpose??

    • @joelplascencia3568
      @joelplascencia3568 4 ปีที่แล้ว +13

      @@mohammedhoque7671 I posted this during my senior year of high school. I'm now a fourth year of college, and I learned the purpose about 2 years ago

  • @Heirophanteye
    @Heirophanteye 12 ปีที่แล้ว +1

    I suppose everyone is entitled to their opinion; which is why I expressed mine. I like that integral calculus has uses. I was simply suggesting that before or perhaps during the explanation of the technique being taught that use of technique in a real world example would be helpful. If I hand you a tool and fail to teach you what it can be used for, I am relying upon you to figure out how to use it. Sure, eventually I may figure it out but it's faster to teach me up front what it is used for.

  • @likesomehero
    @likesomehero 12 ปีที่แล้ว

    You are the reason why education in America needs reform

  • @agent-sz2qj
    @agent-sz2qj 8 ปีที่แล้ว +2

    substitution was my nightmare, but not anymore thanks to you

  • @humiraarroyo
    @humiraarroyo 7 ปีที่แล้ว +4

    thank you! so so helpful and straightforward!

  • @inglesyeses
    @inglesyeses 12 ปีที่แล้ว +1

    hi. i have a feeling you should write the 'd' properly, otherwise people could get confused later with partial differential equations where the d's are written more curly like in your vid... just a thought.

  • @zixan
    @zixan 12 ปีที่แล้ว

    what a good refresher after five years of no math class

  • @sarahholland5980
    @sarahholland5980 6 ปีที่แล้ว

    Completely forgot how to do u-substitution and my exam is in two weeks. Thanks Sal!

  • @EytanWallace
    @EytanWallace 12 ปีที่แล้ว

    Yes. As long as you don't accidentally take the antiderivative in terms of U with the X bounds.

  • @陳桂仁-l4w
    @陳桂仁-l4w 8 ปีที่แล้ว +1

    do we need to +C again in behind of result, sal??? thanks.. you enlighten the enlightenment

    • @zestyorangez
      @zestyorangez 8 ปีที่แล้ว +3

      no because the integral is definite

  • @MrMarkgyuro
    @MrMarkgyuro 4 ปีที่แล้ว

    thank you khan! very good explanation!!

  • @go2grave01
    @go2grave01 12 ปีที่แล้ว

    We use functions for all kinds of things(physics,computer science,astronomy).

  • @danhassler6585
    @danhassler6585 3 ปีที่แล้ว +1

    Great! makes it easy to understand.

  • @emmanuelphiri2086
    @emmanuelphiri2086 7 ปีที่แล้ว

    thanks so much SIR you saved my time

  • @pa800korg92
    @pa800korg92 11 ปีที่แล้ว +1

    AWESOME TEACHER!!!!!

  • @taylorkamann21
    @taylorkamann21 8 ปีที่แล้ว

    👋🏽 Sal you're the best.

  • @boihi1496
    @boihi1496 5 ปีที่แล้ว +1

    This helps so much ty for review

  • @joose9748
    @joose9748 7 ปีที่แล้ว +3

    try showing an example of substitution when you cant use the u' straight on ...these are type "Oh look at that how lucky am I there is u' sitting right next to my u"...

  • @EvilMastermind
    @EvilMastermind 8 ปีที่แล้ว +5

    I freaking HATE integrals. I am litteraly never going to use them in my entire life and I am forced to learn them. Plus to make things worse, every person I watch who is calculating integrals does it completely different somehow. Jus out of the blue every time...

    • @muffemod
      @muffemod 6 ปีที่แล้ว +4

      You will be faced with problems in life. You will be forced to solve them. If you can apply logic and reasoning to solve problems in mathematics, you can transfer those skills into other areas of life.

    • @evanmastermind
      @evanmastermind 5 ปีที่แล้ว

      @@muffemod Wrong.

  • @NightSwipe17
    @NightSwipe17 11 ปีที่แล้ว

    Thank you so much, I finally understand this.

  • @Heirophanteye
    @Heirophanteye 12 ปีที่แล้ว

    Wow. I really need to go back to college. Two master's degrees and I still don't understand the application of this math. What would I even use it for? These videos could be significantly enhanced by starting with a real-world use so that I can start integrating the knowledge by seeing it in context. Then I could understand how the components fit together. Math for math's sake is dry; even for someone who loves learning new things.

    • @eleftheriosgkioulekas1001
      @eleftheriosgkioulekas1001 2 ปีที่แล้ว

      Mathematics IS a real world. You use substitution to do integrals. E.g. it can reduce a wide range of trigonometric integrals to rational integrals. Among other things.

  • @danielpersaud2008
    @danielpersaud2008 10 ปีที่แล้ว

    do u always always always take the new limits?

  • @MiladD25
    @MiladD25 11 ปีที่แล้ว

    At which school level did you guys first did this? high school or college?

  • @Avdbz
    @Avdbz 12 ปีที่แล้ว

    obviously you haven't paid much attention during class, integrals are used to solve,max-mini equations, in fysics, for calculating the area under a curve, it s used extensively in economics alongside with derivatives.... my man if only you would take the time to have a greater look in to every practical thing around us, you would quickly realize that 90% is built upon math... so not math for math s sake is not dry. it s all around us...

  • @jamesbra4410
    @jamesbra4410 6 ปีที่แล้ว

    Nobody learns when you pick the easiest example

  • @EytanWallace
    @EytanWallace 12 ปีที่แล้ว

    Can someone please briefly explain why we need to multiply by 2 and .5 in the beginning?

  • @SerdnaZe
    @SerdnaZe 10 ปีที่แล้ว

    What happened to u=x^2 at the end?

  • @mjstan94
    @mjstan94 12 ปีที่แล้ว

    Saviour Sal Strikes Again! Thanks Sal :)

  • @domestic_god
    @domestic_god 12 ปีที่แล้ว

    Is this A-Level or Degree level mathematics?

  • @sveta89
    @sveta89 12 ปีที่แล้ว

    this is great but i could have used it five months ago ... when i needed it badly

  • @keotshepilemandona9882
    @keotshepilemandona9882 6 ปีที่แล้ว

    THANKS KHAN ......

  • @DRJACOBB
    @DRJACOBB 12 ปีที่แล้ว

    By the way, I remember calculus, but the thing that brought me here was Nightline. The One World School book sounds like it is perfectly aligned with my philosophy--a must read for me. Great job, my friend--and I, too, have an M.B.A. but taught children out of love.

  • @FajorMuckup
    @FajorMuckup 12 ปีที่แล้ว

    I mean you just see its -cos(x^2) without substitution after a while

  • @heavymetaldeath4life
    @heavymetaldeath4life 12 ปีที่แล้ว

    "Math for math's sake is dry; even for someone who loves learning new things."
    Pure mathematicians like G. H. Hardy would strongly disagree.
    Besides, integral calculus is used in areas like electromagnetism, and by extension electrical engineering.

  • @dr.willisofficial8041
    @dr.willisofficial8041 7 หลายเดือนก่อน

    Thank you so much!

  • @badboyesed
    @badboyesed 12 ปีที่แล้ว

    why there is no professor like you in my college ... my wold have bean easier :$

  • @zldms93
    @zldms93 12 ปีที่แล้ว

    정리진짜잘하당ㅎㅎ

  • @ricois3
    @ricois3 11 ปีที่แล้ว

    Sign of you!

  • @ab.bull117
    @ab.bull117 3 ปีที่แล้ว

    Thakn you

  • @odefeoberabor7597
    @odefeoberabor7597 9 ปีที่แล้ว

    Bravo ! Thanks

  • @kane3743
    @kane3743 7 ปีที่แล้ว

    thank you

  • @thoriso1000
    @thoriso1000 10 ปีที่แล้ว +1

    Still confused :'(

    • @OSMADO
      @OSMADO 10 ปีที่แล้ว +3

      you have to study antiderrivatives to get this... it's pretty simple once you practice it and get it through your head

  • @hilalbasibuyuk3459
    @hilalbasibuyuk3459 ปีที่แล้ว

    görselliği bile mükemmel

  • @ngotuan0881
    @ngotuan0881 12 ปีที่แล้ว

    12th grade level mathematics./.

  • @rzxwm10
    @rzxwm10 12 ปีที่แล้ว

    calculus

  • @1234airows
    @1234airows 12 ปีที่แล้ว

    algebra

  • @stopdropandroll
    @stopdropandroll 12 ปีที่แล้ว

    most likely trolling lol

  • @tuber324
    @tuber324 12 ปีที่แล้ว

    Please tell me you're kidding. -.-

  • @wntrsldr5077
    @wntrsldr5077 6 ปีที่แล้ว

    This subject = kms

  • @changjin1229
    @changjin1229 12 ปีที่แล้ว

    쉽다

  • @Shihai0Tensei
    @Shihai0Tensei 12 ปีที่แล้ว

    a-level

  • @eaflores93
    @eaflores93 12 ปีที่แล้ว

    9th

  • @badboyesed
    @badboyesed 12 ปีที่แล้ว

    my life* wold have bean easier :$

  • @w2010rcdas
    @w2010rcdas 12 ปีที่แล้ว

    3rd

  • @iComicE
    @iComicE 12 ปีที่แล้ว

    2nd

  • @tigerclaw3211
    @tigerclaw3211 12 ปีที่แล้ว

    1st

  • @elitesniper3211
    @elitesniper3211 12 ปีที่แล้ว

    This is BORING