00:01
We have a function and we are trying to determine its absolute extrema.
00:05
To do so, we are going to have to look at its derivative.
00:10
Derivative uses the quotient rule, which would be bottom times the derivative of the top, which is negative 1, minus the top times the derivative of the bottom, which is 2x plus 3, all over the bottom squared.
00:36
We will simplify this.
00:38
Let's distribute the negative into the first quantity on top, and then let's foil out the 1 minus x times 2x plus 3.
00:50
And foiling it should give us 2x plus 3 minus 2x squared minus 3x.
01:05
If we want to combine those terms, let's distribute the negative sign, which will give us x squared, the negative x squared, the negative, is with the positive minus 2x minus 3 over x squared plus 3x quantity square.
01:35
Now, critical points are where the derivative is zero or non -differentialable.
01:39
It does happen to be non -differentiable at zero and negative 3, but those were already, first of all, discontinuous points, and they weren't inside the interval anyway...