00:01
Okay, so we have zero, oh, sorry, z going from zero to z equals the square root of four minus y squared.
00:12
Okay, i'm going to put a plus sign there, so you remember it means z is the positive square root.
00:17
But if i square both sides, i get z equals, z squared equals four minus y squared, or y squared plus z squared equals four.
00:27
That's a circle in the yz plane of radius 2.
00:31
Oh, sorry, a half circle because it's only the top half.
00:36
Okay, radius 2.
00:37
So this is the yz plane here.
00:44
It's the worst circle ever.
00:46
Let me drag in.
00:47
Oops.
00:52
Okay, and because there's no x in it, what that does is make this like half pipe.
01:03
Okay, it's still not very circular looking, but that's kind of it.
01:09
Okay.
01:10
And x is going from x equals y to x equals two.
01:16
X equals y to x equals y to x equals two.
01:20
So x equals y.
01:22
Now i'm in the x, y plane, which is like the bottom here.
01:29
Okay, now that's flat on the floor of that cylinder thing.
01:38
Okay, that's supposed to be one solid line there, going through at 45 degrees.
01:45
So x is going from y, so that thing out to x equals 2.
01:52
Okay, so let's put that right here.
01:58
X equals 2...