00:01
All right, so here we're going to be proving a little theorem, and that is that the, if you want to take an integral, we're going to write some points on the point.
00:13
Here we have a at x equals 0.
00:15
We have p in between the two functions, the red and blue function, and then we have a b out here.
00:22
And what we're trying to prove is that the integral from a to b of this whole function, red and blue, f of x, dx, is equal to.
00:33
To the integral from a to p of f of x, dx, plus the integral from p to b f of x, dx.
00:48
Actually a pretty simple proof.
00:51
And in this graph we have the first integral represented by the red and the second represented by the blue area over here.
01:02
So in order to prove this, i did two sums up here using the riemann sum in sigma form.
01:11
And so if we look at this first one, the integral from zero to three of this function whose equation is one.
01:17
And we find the sum via f of x sub k times delta x.
01:23
We find delta x be 3 over n right here...