00:01
Okay, let's find where we have absolute extrema, and we will make a little note here that x is going to be greater than zero because if x is zero or negative, it's outside the domain.
00:12
We can't take the natural log of a negative.
00:15
The derivative would use the product rule, which is first times the derivative of the second, plus the second times the derivative of the first, which is 2x.
00:28
So that simplifies to x plus l n 2x.
00:38
Whoops, sorry, not l n2x, 2x times ln x.
00:47
Now, when is this equal to zero? to solve that, let's factor out an x, which would give us x times 2 lnx.
01:06
X.
01:08
The first solution to that equation is that x equals zero because if the front x is zero, our total is zero.
01:15
But that's not in our domain.
01:16
So we can ignore that value.
01:20
When is one plus two ell and x equal to zero? well, let's subtract the one, divide by the two.
01:34
And remember that the natural log of e to a power equals that power.
01:39
So in this case, if natural log x is negative 1 1 1, then x is e to the negative 1 1 .5...