00:01
Let's find the absolute max and min for this function here.
00:08
This f of x equals cosine squared of x on the interval from zero to pi.
00:14
Now this is how it looks like.
00:16
I rewrote it like this because for some people, it's nice to see that power on the outside, and it's easier to take the derivative.
00:22
And we have to do that with absolute max and mince.
00:26
So let's find the derivative first.
00:29
So we have chain rules.
00:32
We have two cosine of x times a negative sign of x.
00:42
If we put that all together, we will get a negative two cosine x, sine of x.
00:54
Now, we have to find some critical values.
00:56
So we have to set this equal to zero.
00:58
So when the derivative is equal to zero, when is that that.
01:02
The case.
01:04
It's when negative 2 cosine x, sine of x is equal to 0.
01:10
We can get rid of the 2, so then we only have when cosine x is equal to 0, or one sine sine of x is equal to 0...