00:01
All right, so what we're tasked with here is to prove this theorem, showing that the integral of a constant function over a rectangular area, which spans a to b and x and c to d and y, is just equal to this product k times b minus a times b minus c.
00:17
Now, if you're familiar a lot with how these integrals work, a constant function is just going to be a flat plane in 3d space.
00:30
We have this sort of flat plane in space.
00:40
And if we're taking the double integral over the rectangular region, it's just, since it's a flat surface on top, it's just the same as like a rectangular prism in the 3d space.
00:59
So we'd like to use this visualization as a means of helping us solve this problem.
01:06
So in our case, we can use this theory of volumes to solve this.
01:14
So we know that for a rectangular prism, we have the surface ab and cd so that those coordinates, those points make up a rectangular base, and k is just that height...