00:01
Okay, we're finding the max and min of this function on the interval zero to one.
00:06
So we'll take the derivative.
00:08
It's the first times the derivative of the second plus the second times the derivative of the first.
00:18
So factor e to the ax out and you get a minus ax minus one.
00:26
Okay, so it'll have critical values where that's equal to zero or where it's undefined, but it's never undefined.
00:35
E to the x can, e to the ax can never be zero.
00:38
So we're just going to have to solve this for x.
00:43
So a minus ax minus 1 equals 0, minus ax equals 1 minus a.
00:51
So x equals 1 minus a over minus a or a minus 1 over a or 1 minus 1 over a.
01:01
All right, so here's zero.
01:09
Here's one.
01:10
Here's one minus one over a.
01:15
And so we're checking the sign of the derivative.
01:20
So we know that e to the ax is positive, so we don't have to check that.
01:25
We just have to plug it in there...