00:01
When you look at this integral, notice that we have this sine 2 theta without even any power raised on it.
00:09
So notice that that's the derivative, sorry, that's a multiple of the derivative of cost 2 theta.
00:17
And here we have cost2 theta, but that's cubed.
00:20
So we can use that to our advantage, and we're going to use you substitution.
00:25
First, we're going to let u equal cost 2 theta.
00:35
And that means when you take the derivative, du will be equal to negative 2, sine 2 theta.
00:45
Now we're going to just rewrite this so that we have negative 2, sine 2 theta.
00:50
So we're going to, we're going to take a 2 out of that 8...