00:01
So we see that this figure gives us the derivative of a function.
00:04
We want to know on what intervals is the function increasing or decreasing.
00:10
So that's part a.
00:12
We see if we're given the derivative function, a function f is increasing when f prime of x is greater than zero.
00:20
So in this case, we just want to see where the given function, the given graph, is greater than zero.
00:24
That'll be from negative 2 to 0.
00:29
Also from 4 to infinity, or from as far as we can see the graph goes.
00:37
Then where it's decreasing is going to be from negative infinity to negative 2, then from 0 to 2, because it's not technically increasing or decreasing at 2, and then from 2 to 4.
00:58
Then for part b, we want to know where f has a local maximum.
01:02
Or minimum.
01:04
So the local maximums are going to be where the function's increasing at first, so it's positive, and then it's decreasing, so that's negative...