Question

find the volume of the solid formed by revolving the region bounded by y=x^2, y=0, and x=2 about the y axis

Answer 1

Do you know about multivariable calculus perhaps? Or do you want the easy-not-understanding-what-you're-doing way

Answer 2

The answer is 8pi

Answer 3

No, I am supposed to use the Disk Washer method.
I can do it with antiderive(2-y) to get the right answer but I'm pretty sure that's not following th formula I'm given which is outer radius minus inner radius.

Answer 4

Disk Washer?

Answer 5

There's a hole in the solid.. so it's called Washer Method.

Answer 6

So how does this method work?

Answer 7

I do antiderivative from a-b in terms of x or y (y in this case because I rotate about y axis)
pi (outer radius)^2 - (inner radius)^2

Answer 8

\[\int\limits_{a}^{b} \pi (outer radius)^2 -(innerradius)^2 dx\]

Answer 9

I don't how that works, I'm afraid.