Washer method rotating around vertical line (not y-axis), part 1 | AP Calculus AB | Khan Academy

Setting up the definite integral for the volume of a solid of revolution around a vertical line using the "washer" or "ring" method. Created by Sal Khan.

AP Calculus AB on Khan Academy: Bill Scott uses Khan Academy to teach AP Calculus at Phillips Academy in Andover, Massachusetts, and heÕs part of the teaching team that helped develop Khan AcademyÕs AP lessons. Phillips Academy was one of the first schools to teach AP nearly 60 years ago.

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[guinthehouse]

For anyone curious this is used in calculus 2 for college level lol

[spidermand]

His drawing skills have definitely improved from the early integral videos.

[cursodedibujo-maritoaranda]

You can see it like: phi is for the 180º degrees, the semicircle; and square is for the simetry that covers the other negative side of the axes. That's one way to picture it

[davidlancaster]

Way better than my college math teachers!

[MoFo]

what would happen if you rotate around a negative vertical line, (x=-2, would it be 2+y^2)?

[podojeff]

Bruh I’m struggling so hard in Ap calc and my exam is literally in like a month and a half or so 💀

[mrmansir]

at 7:34, is there another way to get the integral numbers (2 and 0) without visually looking at a graph? Graphing it can take a little long during an exam.

[rezanajdi]

I’m doing this in high school and no longer have motivation I have 30 days of school left 😢

[CYCN_Gaming]

So is the outside radius always the function farthest away from the axis of revolution?

[anderswallmark]

I can't find the next video but I got the answer to be pi(191/30). Roughly 6.4*pi area units, a bit much perhaps?

[bobbychan]

I learned this for Calculus AP which is technically a highschool course. Otherwise I believe its a first year Calculus material.

[logiebear]

this is first year calculus for courses like engineering (im doin chem eng)

[dc-nwkv]

what about if the axis is on the negative side? would it then be y^2-2 and sqrt(y)-2 or would it still be the same

[CANOOB]

I'm watching this as a first year Ivy League engineering student, I don't know if engineering is my future if I already need to watch Khan's vids -_-

[FailLegitly]

does anyone know how to do this with respect to x? (using dx instead of dy)?

[seanscientific]

where is the other half of y = x^2????

[blobfishlover]

Wait, why isn't the outer radius 2-sqrt(y) and the inner radius 2-y^2?

[Igio]

Oh snap, I messed this up
Now I have -10 p on my test :S

[river]

I'm sorry I disagree heavily. That is not orange that is salmon pink

[anupriyakumari]

Was that important to make the explanation so messy and confusing...