00:02
Okay, we're given this function, f of x, y, equals 160, y plus 2 is the population density.
00:08
And we want to find the population in the area bounded by these two curves.
00:15
So what we're going to do is just integrate the population density over this area.
00:21
So we need to have a picture of this.
00:23
X equals y squared.
00:25
That's a sideways parabola.
00:28
Okay, let's make it red.
00:32
So it's just like this.
00:35
Oh, i guess i should have marked.
00:38
Okay, so let's say that's 1 -1, and that's 1 minus 1.
00:43
Okay, the next equals 2y minus y squared is also a parabola, but it's going to be going the other way because the y is negative.
00:52
Sorry, the y squared is negative.
00:54
If we factored it, we get y times 2 minus y.
01:00
So it has x intercepts at y, i mean 0 and 2.
01:09
I mean, y intercept, sorry, at 0 and 2.
01:14
All right.
01:15
And also, if you plug one in, you see that, you get one for that.
01:21
So it also goes through this point right here.
01:27
Okay, so it looks like that...