Disc/Washer Method vs. Shell Method (rotated about different lines)

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  • เผยแพร่เมื่อ 19 ธ.ค. 2024

ความคิดเห็น • 447

  • @blackpenredpen
    @blackpenredpen  4 ปีที่แล้ว +303

    Hope this helps with your calculus 1 or AP calc
    Time stamps:
    a) area of the region, both vertical and horizontal rectangles 0:06
    b) rotate about x-axis, 5:58
    c) rotate about y-axis,15:16
    d) rotate about x=5, 21:51
    e) rotate about y=3, 30:56

    • @al-quran9845
      @al-quran9845 4 ปีที่แล้ว +1

      This is not a difficult questions...I know better then you

    • @tanOcotO
      @tanOcotO 4 ปีที่แล้ว +19

      @@al-quran9845 No, it doesn't work that way... stop saying this that's nonsense.

    • @angelmendez-rivera351
      @angelmendez-rivera351 4 ปีที่แล้ว +19

      Mathematician Way Don't be an asshole. This isn't about whether it's easy or not. It's a video meant to help calculus students who are struggling, it's obviously not meant for people such as yourself.

    • @chiragmantri4947
      @chiragmantri4947 4 ปีที่แล้ว +2

      CAN U DO WITH X=3 ALSO??

    • @JB-ym4up
      @JB-ym4up 4 ปีที่แล้ว

      Where's the polar rotation ?

  • @rockyboy5545
    @rockyboy5545 3 ปีที่แล้ว +1289

    You sign up to a college only to learn it from TH-cam. It makes sense. Thank you.

    • @raptorgod77
      @raptorgod77 3 ปีที่แล้ว +5

      I’ll be doing the same

    • @78anurag
      @78anurag 3 ปีที่แล้ว +8

      Wait you learn this in college isn't this a high school course?

    • @jamesarnold3286
      @jamesarnold3286 3 ปีที่แล้ว +38

      @@78anurag this subject is generally learned at either the end of Calc 1 or beginning of Calc 2, or both, but this just depends on what calc 1 and 2 course you took. But people still take calc 1 in college, so it would make sense either way to be learning this in college

    • @78anurag
      @78anurag 3 ปีที่แล้ว +2

      @@jamesarnold3286 I learnt this in Calc 1

    • @brucezhang4912
      @brucezhang4912 3 ปีที่แล้ว +1

      fuck me too and im doing that 2am :)

  • @alanparker9608
    @alanparker9608 4 ปีที่แล้ว +494

    I love how passionate he is when he’s doing maths

    • @malane8541
      @malane8541 ปีที่แล้ว +8

      Ik it’s making me happy how happy he is

  • @Josh-dp6iu
    @Josh-dp6iu 3 ปีที่แล้ว +207

    This is the only person who’s even come close to being able to explain shell method in an understandable way

  • @jackkaczmarski
    @jackkaczmarski 9 หลายเดือนก่อน +56

    This man may have taken the GOAT throne. No shade to The OChem Tutor or Sal Khan (they're both great and have done a lot for me), but NO ONE has been able to teach me washer method until this man. Thank you Blackpenredpen.

  • @panostriantaphillou766
    @panostriantaphillou766 4 ปีที่แล้ว +164

    A washer is a thin plate with a hole (typically in the middle) that is normally used to distribute the load of a threaded fastener, such as a bolt or nut.
    en.wikipedia.org/wiki/Washer_(hardware)

    • @blackpenredpen
      @blackpenredpen  4 ปีที่แล้ว +108

      Panos Triantaphillou omg, thank you! I always thought it as the washing machine washer lol.

    • @alexdemoura9972
      @alexdemoura9972 4 ปีที่แล้ว +17

      Yes, _"Washer method"_ is not after someone's name. But we may suppose it is *not* related to _"washing machine"_ as in _"washer"_ , a person or device that washes something, and as in _"wash"_ verb, clean with water and, typically, soap or detergent.
      It is more related to _"washer"_ , a *flat ring* fixed under a nut or the head of a bolt to spread the pressure when tightened or between two joining surfaces, since we subtract a smaller disc from a bigger disc, we got a *washer disc* or flat ring. Do you gents agree?

    • @gianlucacastro5281
      @gianlucacastro5281 4 ปีที่แล้ว +2

      @@alexdemoura9972 It makes a lot of sense, must be because of this.

    • @christianhaynes7596
      @christianhaynes7596 4 ปีที่แล้ว +22

      I actually laughed out loud when he said washing machine, i thought he was joking lol

    • @exequieldelantar9641
      @exequieldelantar9641 3 ปีที่แล้ว

      May I ask.. Is circular ring method and washer the same?..

  • @josueolivos3783
    @josueolivos3783 หลายเดือนก่อน +2

    can we appreciate how flawlessly he switches between black, red and blue expos to make it clear to the viewers where each term is coming from??? thanks my guy!

  • @maybritSortiz28
    @maybritSortiz28 2 ปีที่แล้ว +72

    I cannot express enough my gratitude for your videos! I struggled to conceptualize washers/disks and shells, but with your thorough explanations, I could tackle these questions with ease. Thank you!

  • @joabnyabuto6041
    @joabnyabuto6041 2 ปีที่แล้ว +25

    this man just taught me three weeks' worth of class in under an hour. That's crazy

    • @takeshisatou2371
      @takeshisatou2371 5 หลายเดือนก่อน +2

      3 weeks? my university taught us this in less than a week and expect us to be able to understand it lol. My university's curriculum is insane. (Not gonna expose my university, but it's 1 of the top 5 universities in asia as of 2024.)

  • @Theonlyway1445
    @Theonlyway1445 4 ปีที่แล้ว +181

    If this guy didn’t exists, I would fail all of my calculus courses.

  • @philrunninger2359
    @philrunninger2359 4 ปีที่แล้ว +66

    Great video! I love all the TH-camrs making math more easily understood. Just a point of clarification... "Washer" refers to a fastener used in combination with a bolt and nut, not a washing machine.

    • @blackpenredpen
      @blackpenredpen  4 ปีที่แล้ว +58

      Omg, that washer?!
      I always thought that as the washing machine washer lol

  • @elias78910
    @elias78910 ปีที่แล้ว +2

    Thank you. It really helped me

  • @hazemalsabagh7855
    @hazemalsabagh7855 2 ปีที่แล้ว +14

    I really appreciate that you dive deep into simple questions to ensure the fundamental understanding of the topic.

  • @shartypants1234
    @shartypants1234 15 วันที่ผ่านมา

    I have my calc final tomorrow and have spent the past week trying to understand the shell method to no avail before I found this video. you made it so easy to understand. thank you for posting lessons like this and helping us struggling students!!

  • @AustinHoelscher
    @AustinHoelscher 2 ปีที่แล้ว +19

    Hands down best video about this on TH-cam.
    Subbed! :)

  • @sukaygisiz8052
    @sukaygisiz8052 3 ปีที่แล้ว +5

    i've never commented on a youtube video before, but dude i was depressed at my final exam week and you made my day with your smile. thank you! keep doing it. you are amazing at your job.

  • @tanOcotO
    @tanOcotO 4 ปีที่แล้ว +45

    Yes, thank you, we skipped all of this because of the pandemic in my calc class

  • @ld-vt9sn
    @ld-vt9sn 3 ปีที่แล้ว +14

    I can't believe that a few years ago I watched your channel, and I had no clue what all those hieroglyphs were on the whiteboard, And now I'm watching your videos for an explanation! keep up the amazing work, I love your videos! thanks!

  • @incognito6751
    @incognito6751 3 ปีที่แล้ว +12

    Ever since The Organic Chemistry Tutor started paywalling his videos, I've been struggling in math. Thank you for this.

    • @sihlesamukele4556
      @sihlesamukele4556 3 ปีที่แล้ว +2

      i thought i would never find someone like him, but guess what i just found the one BLACKPENREDPEN

  • @banthatiwisdom6783
    @banthatiwisdom6783 3 ปีที่แล้ว +2

    Thank you for your time. If it wasn't you I would have not understood all these. *Highly appreciated from South Africa*

  • @simatwokirwa4500
    @simatwokirwa4500 2 ปีที่แล้ว

    Comment on 10:44 - Washer method because the shapes do not look like wash-machine BUT because the outer shaper/graph relates to WASHER y = root-x and the inner shape y = half-x relates to BOLT that goes into washer or ring. .. .very good intuition on finding area / volumes under curves using integration. .. good job.

  • @silasjoao8953
    @silasjoao8953 4 ปีที่แล้ว +30

    man i'm brazilian and my classes were suspended due to the covid-19 pandemic, your classes have helped me a lot, here we see this in calculus 2 continue with this incredible work and may god bless you

    • @panovitch
      @panovitch 4 ปีที่แล้ว +1

      kkkkkkk br realmente ta em todo lugar

    • @rafaelb.333
      @rafaelb.333 4 ปีที่แล้ว

      Acompanho esse canal desde que comecei a estudar matemática direito hue

    • @andrewcarvalho9158
      @andrewcarvalho9158 4 ปีที่แล้ว

      Isso aí é cálculo 2?

    • @panovitch
      @panovitch 4 ปีที่แล้ว

      @@andrewcarvalho9158 sim mano, calculo de volume de solidos usando integral

    • @LuizFernando23250
      @LuizFernando23250 3 ปีที่แล้ว

      @@andrewcarvalho9158 Eu vi em cálculo 1 mesmo

  • @DavGre
    @DavGre 2 ปีที่แล้ว +3

    Thank you for using the same two functions for the different examples, I hate when some videos try to explain the different rotations but pick a bunch of different functions for each method and rotation, this makes it crystal clear to understand the fundamental concepts without having to rewatch or pause a lot.

  • @Alex-bc3tt
    @Alex-bc3tt 2 ปีที่แล้ว +7

    This video needs to be the first thing lectures show to their students 🤣🤣🤣Very much descriptive and straight to the point, it even helps train the mind how to visualize the solids of revolution. Keep up the good work 🙏🙏🙏

  • @andrewa7952
    @andrewa7952 3 ปีที่แล้ว +15

    A great help visualizing when online classes don't do nothing!

  • @ladyeillie671
    @ladyeillie671 5 หลายเดือนก่อน +1

    For someone who has been confused between the shell and disk/washer methods, this was very helpful for comparison.

  • @milk6489
    @milk6489 ปีที่แล้ว

    bro you dont understand how much i love your explaining and the way you teach, ive never thought id give props to a tutor on youtube but you are levels beyond anyone else on youtube teaching

  • @narutofan2010san
    @narutofan2010san 7 หลายเดือนก่อน +1

    You are a king! You explained chapter 7.2 of the Stewart Calculus textbook in 30 mins. Thank you sir!

  • @marcusmoulia639
    @marcusmoulia639 2 ปีที่แล้ว +8

    you can really see how passionate he is for teaching math through this video. great work, keep it up!!

  • @fkncompton7124
    @fkncompton7124 4 ปีที่แล้ว +20

    Learned this like 2 years ago and watched the whole thing anyways for a refresher lol good video

    • @Sg190th
      @Sg190th 4 ปีที่แล้ว +3

      Haha same. I didn't get a full grasp of learning this but it was really fun. Everything in previous math used for calculus. Can't believe I thought it was generally difficult.

  • @epictrooper2568
    @epictrooper2568 3 ปีที่แล้ว +7

    You made this so easy to understand. Up until this point I did not really understand these methods at all but now I actually understand what I'm doing. Thanks!

  • @rachelkiss302
    @rachelkiss302 4 ปีที่แล้ว +11

    God Bless his soul. He just saved me for my test tomorrow. Thank you for your service sir.

  • @xgyra
    @xgyra หลายเดือนก่อน

    I had the weird sense that I should study ahead over the weekend and ended up getting sick on the first day of this week. The notes I took over this video are going to carry me.
    🙏 (Thank you! This was an incredible guide.)

  • @jamerthegamer13
    @jamerthegamer13 4 หลายเดือนก่อน

    9:30 man i never thought about them as two different
    disk methods, that’s so much easier thank you!

  • @105-ssaiswaroopa9
    @105-ssaiswaroopa9 2 ปีที่แล้ว +1

    I am just getting interest on the subject, just by seeing him...what ah positivity his face has!!!! Wow!!!

  • @chasemckinley2
    @chasemckinley2 ปีที่แล้ว

    I'm blown away that this much visual clarity on volumes of solids of revolution came from a video without some 3D graphics computer program involved. Loved the vid/thanks for making this!

  • @maggiedriggs9642
    @maggiedriggs9642 2 ปีที่แล้ว +4

    he somehow made me smile doing math! such a kind and clear teacher, thank you for these lessons!

  • @zunairarahat
    @zunairarahat ปีที่แล้ว

    I blanked out for 2 hours trying to learn this in class and fully understood you in less time. Thank you so much!

  • @aftabafii.
    @aftabafii. 2 ปีที่แล้ว

    Clean explained everything without any confusion give me a lot of concept without questioning answering

  • @faroseflinch4053
    @faroseflinch4053 ปีที่แล้ว

    I'm having calculus test tomorrow,this help more than 2 hr lectures,wish me luck

  • @kenokai.
    @kenokai. 3 หลายเดือนก่อน +1

    Exam in like 2 hours and I swear I have watched this video along with a few other of his like at least 3 times each and It has really helped me get the logic down. Fingers crossed I can apply the logic I learned on the exam

    • @blackpenredpen
      @blackpenredpen  3 หลายเดือนก่อน

      Best of luck!!

    • @eir6791
      @eir6791 19 วันที่ผ่านมา

      howd it go i have an exam in 35.5 hours 😭

    • @kenokai.
      @kenokai. 19 วันที่ผ่านมา

      @@eir6791 went well, 26/30! goodluck!

  • @CarlosMolahlehi
    @CarlosMolahlehi ปีที่แล้ว

    you have my respect sir. i now have the full understanding of shell and washer method because of you.all thanks to you sir

  • @michaela6396
    @michaela6396 2 ปีที่แล้ว +1

    One of the best instructors I have had help me practice Calculus. Thank you for your videos

  • @BelindaCho
    @BelindaCho 3 หลายเดือนก่อน

    love u broooo, youre strongest math teacher Ive ever seen

  • @BalaMurugan-hk2gd
    @BalaMurugan-hk2gd 3 ปีที่แล้ว

    You made me so much happy. I could not describe in words because my English is so poor. Thank you dude.

  • @xioxy7193
    @xioxy7193 3 ปีที่แล้ว +1

    I have a test about this today. The video recomendation was brilliant i think im ready now for it. Thank you Blackpenredpen.

  • @TDL0347
    @TDL0347 3 ปีที่แล้ว +1

    I were studen 2000 years . But you are my idol

  • @bobbob3659
    @bobbob3659 9 หลายเดือนก่อน +1

    Mr.blackpenredpen you are the goat!!!!!!!!!!!!!!!!!!!!!!!

  • @pr0dsatya
    @pr0dsatya 2 ปีที่แล้ว +1

    When I get my degree and start earning a salary I will certainly be donating to this channel

    • @blackpenredpen
      @blackpenredpen  2 ปีที่แล้ว

      That’s very nice of you. Thank you. 😃

  • @marazali1816
    @marazali1816 2 ปีที่แล้ว +4

    this has been a great help to actually understand the concept, i am very thankful for this video my good sir

  • @thekishorkhairnar
    @thekishorkhairnar 3 ปีที่แล้ว

    Excellent video...
    Perfect explanation...
    Love from India 🇮🇳 ❤️

  • @makke2170
    @makke2170 4 ปีที่แล้ว +2

    This is probably one of the best, if not the best, ways to learn maths. Fantastic video!!

  • @onion-brawlstars9792
    @onion-brawlstars9792 3 ปีที่แล้ว +1

    this video integrates everything you need to know to ace solid of revolution

  • @Nigixmitama
    @Nigixmitama ปีที่แล้ว

    You just saved me 25% of my whole semester, thank you!!

  • @Ducky_shades
    @Ducky_shades 2 ปีที่แล้ว

    For love of calculus keep on writing my blackpen and solving my redpen

  • @acoustickunal578
    @acoustickunal578 4 ปีที่แล้ว +2

    this video helped me a lot today was my class and hardly understand anything you helped me thanks!!

  • @mrsamiam7872
    @mrsamiam7872 10 หลายเดือนก่อน +1

    Math exam tomorrow thank you so much bro 🙏

  • @geoffreybwalley6498
    @geoffreybwalley6498 3 ปีที่แล้ว +3

    Wonderful!! I was struggling to understand the topic
    But you make it easy, I tackle questions from any angle
    Your explanation is Amazing .

  • @justinhastie3851
    @justinhastie3851 3 ปีที่แล้ว +1

    I really appreciate your enthusiasm. You breaking it down like this really shows how easy it is. Thank you so much :)

  • @gilbertley1309
    @gilbertley1309 2 ปีที่แล้ว

    One of his best videos for sure!

  • @samuellim4956
    @samuellim4956 3 ปีที่แล้ว

    thank you for helping me! You are better than my prof!!!!!!!!!!!!!!!!!!!!!!

  • @jonascaburnay4839
    @jonascaburnay4839 7 หลายเดือนก่อน

    i was having a hard time reviewing my instructor's pdf, thank you for this!~

  • @aliatejeda6210
    @aliatejeda6210 10 หลายเดือนก่อน

    you just saved my math grade! THANK YOU!!!

  • @The1RandomFool
    @The1RandomFool 4 ปีที่แล้ว

    I did a volume of solid revolution around the line y = -x just to crank things up a notch. It took a while since I had to rotate the region clockwise π/4, then do a revolution around the y-axis with shells. It's a bit of work, but doable. Unless I made a mistake somewhere I got 52/15 * √(2) * π.

  • @austin7843
    @austin7843 ปีที่แล้ว +1

    You deserve the Presidential Medal of Freedom.

  • @annierod
    @annierod 4 ปีที่แล้ว +3

    I was able to understand the concept thanks to you 🙏

  • @gianninagarcia6842
    @gianninagarcia6842 2 ปีที่แล้ว +3

    YOU JUST SAVED ME! ALL HAIL!

  • @YaraHMY
    @YaraHMY 2 ปีที่แล้ว

    Thank you so much, the book explanation is difficult to grasp.

  • @shemayrays7632
    @shemayrays7632 4 ปีที่แล้ว

    Thank you, I learned a lot. Keep up the good work. Support here from the Philippines.

  • @elshaddai6648
    @elshaddai6648 4 ปีที่แล้ว

    Find the envelope of a straight line x/a +y/b=1 where the parameted a and b related by the equation a^n +b^n =c^n

  • @biggerthaninfinity7604
    @biggerthaninfinity7604 3 ปีที่แล้ว

    Here is one guy who makes math fun

  • @kenpachicg
    @kenpachicg 2 หลายเดือนก่อน

    This just might be what I needed for my Calc 2 test today

  • @jaredayala8295
    @jaredayala8295 7 หลายเดือนก่อน

    Personally, I would just use two integrals. Integrate first with respect to y. (x/2 =< y =< sqrt(x)) and then integrate with respect to x (0 =< x =< 4)

  • @yeellee4780
    @yeellee4780 4 ปีที่แล้ว +1

    Just in time for my AP calc exam. Thank you very much

  • @enqiwu5307
    @enqiwu5307 ปีที่แล้ว

    Thank you so much for creating these content. I have been failing my Calc BC class until I watched your videos :)

  • @Araxatu
    @Araxatu 4 ปีที่แล้ว +2

    I learned more about calculus in this video than I learned in college in one year

  • @collinnovak8914
    @collinnovak8914 3 ปีที่แล้ว +4

    this man draws better than my professor at Purdue

    • @stimulus7222
      @stimulus7222 3 ปีที่แล้ว

      Hahha. I will come back and verify this comment after next fall😎👏

  • @MFRSIAM
    @MFRSIAM 3 ปีที่แล้ว

    this video fucking save my life , so many thanks man a truly lifesaver.

  • @brownwater6212
    @brownwater6212 4 ปีที่แล้ว +10

    I'm not in Calculus yet, but I love watching your videos regardless.

  • @rada4917
    @rada4917 หลายเดือนก่อน

    seriously ur videos help so much

  • @badiosogenyl4948
    @badiosogenyl4948 2 ปีที่แล้ว

    the washer I think is disc cylindrical washer since it is a 3 dimensional figure.. great explainantion.. great help in times of online class where onliine modules are so difficult to understand

  • @nunoskid153
    @nunoskid153 ปีที่แล้ว

    YOURE THE BESTTTT THANK YOUUUU FINALLY SOMEBODY DID THIS RIGHT

  • @suteguma0
    @suteguma0 ปีที่แล้ว +1

    bro teaches me more than my Calculus class 😭

  • @semajzomollo3286
    @semajzomollo3286 ปีที่แล้ว

    you were oddly entertaining and instructive I learned a lot thank you

  • @Anna-qp1fi
    @Anna-qp1fi 3 ปีที่แล้ว

    Man, I really love this guy!

  • @RevToGo-tv
    @RevToGo-tv ปีที่แล้ว

    4 years in college and this is the 1st time I understand disk washer method and shell method.

  • @potatoeater8014
    @potatoeater8014 3 ปีที่แล้ว

    didnt understand disks+washers until this video, thank you bprp :OO

  • @christopherdeckinga2421
    @christopherdeckinga2421 ปีที่แล้ว

    I figured it out... at minute 30:56, we integrate [0,4] because x=4 is the point of intersection.

  • @akolangto8225
    @akolangto8225 3 ปีที่แล้ว

    Thank you so much sir! This is what im looking for, explaining the concept and derivation of the formulas especially area and volume .
    From the philippines

  • @purplelala2
    @purplelala2 ปีที่แล้ว +1

    Great video!! Helped me figure out how to set up my equations

  • @isaiahlobert7843
    @isaiahlobert7843 3 ปีที่แล้ว +1

    You are a life saver my man!

  • @rosendjavera7734
    @rosendjavera7734 3 ปีที่แล้ว

    You are such a genius ,i didnt this topic was this simple❤🙌

  • @aiden_villa
    @aiden_villa ปีที่แล้ว

    loved the martini glass joke lol. also, very helpful video. wish me luck on my test tmrw!! lol

  • @allaylu2802
    @allaylu2802 4 ปีที่แล้ว

    This was a very well explained video. I was not able to do it on my own until this video.

  • @ezachle
    @ezachle 4 ปีที่แล้ว

    this is so much more clearer than what my teacher had taught me. thank you!

  • @hillsidebilly4649
    @hillsidebilly4649 2 ปีที่แล้ว

    This video is incredibly good.

  • @kuppuswamyravi5714
    @kuppuswamyravi5714 3 ปีที่แล้ว

    Very good presentation
    I understood very well

  • @kennymccormick6846
    @kennymccormick6846 3 ปีที่แล้ว +2

    Holy shit, i think this video just saved me. Thank you!

  • @juliadeluis1132
    @juliadeluis1132 2 ปีที่แล้ว +3

    Thank you for explaining this!!

  • @FelixTheForgotten
    @FelixTheForgotten 2 ปีที่แล้ว +2

    "Just like washing machine, Washer has hole in the middle." - BlackPenRedPen - 2020