0:00
I'm graphing first.
00:01
So i'm going to do part b.
00:03
So when i see taking this function, y equals, well, i know it says x, y equals 5, and i like to write things as functions would be y equals 5 divided by x.
00:20
And the way that would be written or graph to be something like this.
00:24
And you can pick out some key points like when x equals 1, you would get 5 for y, or you can have if you know x equals 5 then y would equal 1 but we actually don't even care about that we have the values between 2 and 8 so that's y equals 2 and then y equals 8 would be up here and we're revolving around the y axis so basically we have these disks in here i don't know if they want you to show those disks but basically the graph would look something like this.
01:06
So there's part b.
01:08
So how would you set up this integral? well, first of all, you should have actually solved this problem for x.
01:18
Because it's the disk method, where you're just finding the area of all those circles and the area form is pi r squared.
01:27
And so if you're doing this properly, the s is the integral from 2 to 8.
01:36
And this pie is a constant, so just write that down.
01:39
And then the function is...
01:41
Oops, i wrote the wrong thing down.
01:45
Ah, i thought i hit the racer.
01:48
There we go.
01:51
5 over y.
01:53
That thing is being squared.
01:55
D -y.
01:56
Now, at this point, it would be up to you.
01:59
How you would.....