Application of Integration--Volumes by Disks/Washers

Sample problems and introduction

[@RonaldComeau-zb5qk]

Great

[@kathyho4762]

thanks! EXTREMELY very helpful. I'm currently reviewing for preparation of my calculus AP test. I will be binging your videos for the next couple of weeks haha! :)

[@yankeehank1897]

At the 2:27 mark, with respect to the graph, wouldn't it have been clearer to denote the Area as pi*y^2 instead of pi*x^2?

[@kellyLOLclarkson]

how did he get (4,4) ? at 8:56

[@ranblake3165]

Solid !

[@boagomoemedidavid6893]

how did you find root 5 10.05

[@newggyy]

How did you get square root of 5?

[@rishavmandal285]

Newton Jay 2.254

[@hasssankhattak5136]

Y u didn't take -2 while fndg x

[@ahmedzain1660]

6:16 Is the integration correct?

[@Mathtermind11235]

Hi, Ahmed, I hope you are well. Yes, the integration is correct. Good luck in your studies!

[@Alex-ij1km]

For anyone trying to get help from this: the one with e^x from [0,2] is actually a WASHER question, not a disk one. This guy doesn't know what he's doing. If you picture it rotated about the line, then the shape will have a cylinder cut out of it, so therefore the cross sections will be washers. Then, it would be pi *(integral from 0,2) R^2 - r^2 dx. Which is e^2x - (-1)^2 dx.

[@Mathtermind11235]

Alex, I'm sorry if the video wasn't clear, but I did not say that an area bounded by the curve AND the x-axis was being rotated around the line y= -1. It was simply the curve being rotated--and is therefore a solid. I have clarified the video, and I appreciate the comment.

[@Alex-ij1km]

thanks Eric. I wasn't trying to come off as rude or anything. I was just used to doing regions bounded by axes and incorrectly assumed that it would be the same. I didn't want anyone else to run into the same problem. Appreciate it