00:01
I think this is another problem that has that typo in there.
00:05
I think instead of where it says, in the y -axis, i think what it's actually supposed to say is in the x -axis.
00:16
But i think we are revolving around the y -axis.
00:22
So as i'm looking at this, so double check this typo, see if that's really what's meant.
00:32
Because we have y equals 2x squared.
00:35
I think they want you to revolve around the y -axis, but it wouldn't make any sense to say x equals 2, which is a vertical line, and the y -axis.
00:46
It makes more sense to say the x -axis.
00:50
And to take this region in here, and let me use red, and show you why it's going to be the washer method.
00:58
Because you have this empty space, i hope you can see the washer that's inside of there.
01:03
So this volume will be equal to pi, the integral will be, i'll figure that out in a second, of a function squared minus another function squared.
01:13
And because we're going, basically because we're revolving around the y -axis, the function that's further away is x equals 2.
01:24
And what i need to do is take this equation and solve for x...