The difference between disk, washer, and shell method 

Hey guys, I originally made these youtube videos to help my classmates before a Calculus 2 test that we had 3 years ago. But seeing how far it blew up really encouraged me! I've decided to upload more math tutoring vidoes to help you guys! I'll be sure to upload more math tutoring videos focusing on Calculus 1, Calculus 2, Geometry, Trigonometry, and Algebra. Thank you guys so much for all the love and support! I am so happy that I could help you guys! More videos coming soon, I promise.

God Bless this woman. She just saved me for my exam tomorrow. Thank you!

best video ever in distinguishing between the 3 ways.

Wow! This is what math teachers should be like! You organized everything so that we could actually understand the concepts and then make the connections to how and why the problem works the way it does. God bless you!! Keep on making videos please ❤️❤️❤️ Update: I got a 95 on my test 1 because of this. Now I’m back at it for finals on Monday! Wish me blessings!

3 years later and she still saving lives, God bless you

I am in Calc 2 right now and had no idea when to use the different methods until I watched your tutorial. I spent the last two days in the library looking for hints on the internet and nobody made any sense. This video makes everything so clear. Thank you!!!

This is such a nice way of describing when to use each method! I definitely appreciate it!

Unironically one of the most clear and concise calculus videos I've ever seen. If you aren't already you should consider teaching.

i was so confused on when to use the washer disk and shell methods. im a university student lol. this video helped me out so much. thank you so much!!!!!

3 years after being posted and your video is still helping me get through calc 2 in college thanks so much!

You ma'm, are a true hero. GOD BLESS THIS WOMAN TENFOLD! THANK YOU!

I'm studying for my calc 2 midterm and was looking for a resource to help me with volume of disks/washers and shells. This was a godsend! Thank you so much for explaining it so clearly in such a way that we can easily understand it!

Best video yet! Very simple easy and understand. This is like the 25th video I've watch and by far it is the best. Thank you so much! 🤗

This flow chart is a life saver for Calc! Thank you so much for creating this. I really appreciate it.

this is the best easy going and most straight forward video ive seen thankyou!

Even though I have watched hour-long videos on RU-vid and attended lectures. This video summed up everything I needed to know about finding the volumes of solids of revolutions. I just subscribed. I will share the video with friends and many more. I can not wait to watch more of the videos on this channel. Thank You.

Amazing video, this was the one concept that kept tripping me up. Makes so much sense now. You are a gentlewoman and a scholar.

This is probably the third time I commented on a RU-vid video in 10 years. I just had to, this is amazing. Calculus 2 is known to be one of the hardest classes you will ever encounter but you did an amazing job at explaining it. I am going to show this to my teacher because it's just too good. Thank you for the hard work you put into this video.

For real! Thank you so much for making this! Been spending forever trying to figure it out.

Hey guys, so a lot of people were asking what a strip is. A strips is the rectangle that I draw from the function to the axis of rotation. Like someone else in the comments pointed out, the strips are the rectangles or bars that are used to make approximations. The strip rotates 360 degrees to form a 3-D shape from 2-D rectangles. When you create infinitely many rectangles in the bounded region we can get closer to exact values.

Oh my god, it's a very difficult material but you manage to simplify it. What a phenomenal video. You've just helped me to understand the materials under 15 minutes. This video deserves to be on top of the searching lists so that people can notice it. You have just saved me and my friends to comprehend the topic. Hopefully, you'll become one of the best math youtube channel tutorials in the future. I'll be watching A.S.A.P. Thank you so much 😃.

You are a true educator that want her student to understand what they're studying. Thank you for this. I can differentiate the three methods now. God bless you!

Bless you oml you are such an easy person to listen to. Was reviewing for calc exam soon and this video summarized one of those sections extremely well!

Thanks Ashley, your flow charts and examples made my homework really simple!!! Thanks for posting this.

I was still a little confused by these concepts until I watched this video. Great explanation. Thank you!

Excellent! It's been a while since I dealt with solids of revolution from calc 2, but I needed to review this topic for something. I programmed the formulas in my calculator, and the only thing I needed to remember is when to use washer vs shell. This video cuts to the chase and is more helpful than any other I've seen. However, I think there's a simpler way to think of it. I only have two programs for this in my calculator -- one for washer, one for shell. There's no need for "disk". Disk is just a variation of washer. In my washer code, I enter a value for any separation from the rotating axis. When there's no separation, the value is 0 (creating the "disk"). This is also how I've seen it taught in various calc 2 texts -- just washer vs. shell. I think it's easier to think of two choices rather than 3.

Thank you so much. I went through like 2 years of calc without knowing this. Now Im preparing for a calc 2 final and this is CLUTCH. The table you showed in the beginning is so helpful and organized. Thank you so much

It is the best video for distinguish between disk, shell and washer method. Nice explanation 😊😊

Excellent explanation🎉

even a teacher has never explained like this. this tutorial was so helpful :)

Thank you so much! This has been the best video on describing volume, you've helped me tremendously. My grade thanks you 😭✨

very helpful, thanks for taking the time to explain this.....makes choosing the method very simple ( I struggled with visualizing these rotations at times )

I have to say, well done. This will help a lot of people.

I'm sitting here the day before my test confused as heck. Your flow chart is literally saving me XD. It's so much clearer now. Thanks so much for posting this video ^^

this video made such a complicated concept super simple to me. my professor and the textbook made it sound like nonsense. thank you so much, i wish i found this video sooner.

I never comment on anything but this video was super helpful. Thanks!

This is the kind of teaching I can learn from.

Dude. When I say thank you, I mean THANK YOU!! I hope you have a blessed day.

I have an exam 7 hours later, God bless this video for helping me cram

Well explained! this kind of teaching is what I like the most

Flow chart is awesome. Definitely using this. Thanks!

Best explanation! Thank you for sharing your thoughts 🙏

Thank you so much! My tutor shared this with me, and w/ some more practice, I believe I'll finally discern which right method to use! God Bless 💗

The hidden heroes of RU-vid strike again! Have my first calc 2 exam in two days. Thank you so much!

God bless you and your clarity, much needed thank you!!!

Amazing video, explained everything super simple and easy to understand

This video helped so much! I have watched a few other videos about this and I couldn't understand, but this was the first video that made sense. Thank you!!!

First video that actually made sense to me, thanks!

I APPRECIATE YOU SO MUCH, it’s been challenging understanding this concept in class but your videos help so much!!!

That is so nice and precise. It helped me prepare for my exam. Thank you!

I have spent hours watching videos about this subject and I couldn’t grasp the concept. In 12 minutes you helped me understand it. Thank you!! Your teaching method/style is amazing!

You have just saved my life, thank you so much 🙏🏽

I’ve got to get me one of those flow chart thingys. Excellent job on the video - thank you

Thank youuuuu so muchhh ashley! i was having a problem in picking which formula to use. Your way has solve my problem,lots of love to you^^

Thank you so so so much. You made everything perfectly clear!!

AAAAMMMMEEEEZING Well organized. imagine if you was my Professor. you are more than my professor Thanks a lot. a have got D on my quiz but in my next exam for sure I will get A.

You saved my life ❤️❤️ from Dubai

Fr thanks, my Calc AB teacher is great but she didn’t do a good job teaching this lesson imo, I’m not very geometrically inclined so the flowchart and the idea of the curve “sitting” on the axis of rotation really helped me! Thanks and good luck on the channel :)

thank you so much you really help me a lot god bless you and more blessings to comeee💕

I immediately lower the volume of my device when you're about to draw a strip haha anyways, thank you for this, you delivered this concept well that made calc2 becomes easy

This was beyond helpful!! Thank you so much

Thank you so much ! This explained the difference so well in just a couple of minutes.

Calculus test in 3 hrs here we gooooo thanks for the video! Very nice n easy to understand

I just learned so much it's all clicking now!!! Thank you!

You are literally an angel, I have an exam in two days and this all finally makes sense 💛

this video was extremely helpful! Thank you

what an absolute GEM of a video, thank you!

Great video, it helped a lot. Just one little mistake, for the problem y=3x-10 and y=6-x the lines are switched so it tripped me up as i tried graphing the functions by hand. Besides that all great stuff

Helped me a lot.......THANK YOU SO MUCH!!!

Late, and just finding about this method as I am doing this in Calculus 2. Love the method however one thing is i believe y= functions should have a horizontal strip as the function is defined for a range of x-values, and the y-values correspond to the output of the function at each x. So, horizontal strips (which focus on how y varies for each x) are the natural way to analyze these types of functions. In contrast, x = functions would use vertical strips since they are defined for ranges of y-values and show how x depends on y.

Thank you for breaking it down in a fast and easy way.

what a god.... literally have a quiz tomorrow big help!!!! thank you

thank you very much this is just the right thing i was looking for for my test tommorow ty :D

Thank you so much for making such a nice video! Very patient in your explanations. Have a great day and keep up the helpful videos! Very helpful once again.

you have saved lives

Best explanation! thank you for making this

u just saved my life i love you

You just helped me so muchhhh 😩 you the real MVP 😏😊

most under rated math video

Amazing video and organization thank you

Thank you so much!! After seeing this video, I know I would not fail my calculus exam tomorrow

Shout out to you girl! this was mad helpful

love seeing smart black women! thank you so much !

Very helpful! Thank you!

This is really helpful! Thank you!

thank you teacher of the day

You just saved me omg thank you for making it so simple!!!!!!

I loved the explanation really understood everything 🎁

Thanksss ❤️❤️you make it clear

nice explanation

Thank you so much you don't know how much you have helped me ♥

i have exam tmr and this literally saved me !!

Well explained⭐

you are an angel ! thank you so much for explaining this so clearly :)

Thank you I studied this with a tutor and the teacher but never understood it 😂😂

really well put together thank you so much

Thanks, Merci,شكراا in all language i appreciate your work

hecka good video, this wasnt out when i took calc in high school, but good thing its out now!!

Still helping people five years later ashley

You are a goddess! Thank you so much!