00:01
So i have a function f of x and that's equal to x cubed minus 6x squared minus 63x plus 9.
00:17
And in a, i am on the interval negative 4 to 0.
00:24
So i'm going to first find my endpoints, or i should say the y -coordinate of the endpoints.
00:44
So if x is negative 4, i'm going to get out 101.
00:48
If x is 0, i'm going to get out 9.
00:52
Now i'm going to take the derivative of that function to find my critical value.
00:58
So just use power rule 3x squared minus 12x minus 63.
01:05
I'm going to set my derivative equal to 0 and factor out a 3.
01:17
And then i'm just going to continue factoring.
01:20
So i have x minus 7 and x plus 3.
01:24
So now i have to test those points, negative 3 and 7.
01:30
So i'm going to take them and put them into my original function.
01:38
So i have 117 and negative 383.
01:45
Now i'm going to answer the absolute maximum is going to be the point that has the highest y -coordinate, and that's 117...