00:01
In this question, we're going to sketch the region that's enclosed by the given curve.
00:03
We're going to integrate with respect to either x or y, and then figure out what the area of the region is.
00:10
So first, i have y equals x squared minus 3x.
00:16
What shape is that? that is a parabola that opens up, since there is a positive leading coefficient on the x squared, which means these two answers can't be correct.
00:27
It's got to be either answer choice 3 or 4 down here.
00:31
If you look at y equals 3x, that's a line that's passing through the origin with a slope of 3.
00:40
It has a positive slope, and so therefore, it's got to be this option here as my graph.
00:48
Now i'm trying to find the area enclosed by these curves.
00:51
I'm going to start by figuring out where do they intersect.
00:56
So we're going to set x squared minus 3x equal to 3x.
01:01
I subtract 3x from each side.
01:03
X squared minus 6x equals 0.
01:05
I factor out an x.
01:07
X times the quantity of x minus 6 equals 0.
01:10
So i'm getting x equals 0 and x equals 6.
01:13
Now, those are my intersections.
01:17
I am going to integrate in the order of top function minus bottom function.
01:22
So my top function this time was the line 3x minus the bottom function, which is the quantity of x squared minus 3x dx...