00:01
So from the given graph, we know that f prime is positive on these some intervals and it's negative on the other intervals.
00:14
So f is increasing on 1 to 6 and union with 8 to infinity.
00:28
And it's decreasing on 0 to 1, union with 6 to 8.
00:36
So that means we have a local max at x equals to 6 and we have a local minimum.
00:48
So we have two local minimums at x equals to 1 and x equals to 8.
00:54
Now for the inflection part, we know that f prime, f prime is decreasing.
01:00
So f1 is increasing on 0 to 2, on 3 to 5 and on 7 to infinity.
01:14
That means the f is concave up.
01:18
Because if f prime is increasing, that means the second order derivative is positive, so it's can't keep up.
01:24
And the f prime is decreasing on 2 to 3, union with 5 to 7.
01:30
So it's concave down.
01:35
And that means we have some infraction point at x equals to 2, 3, 5, and 7.
01:51
Because at each point, the concavities are changing.
01:57
So we can graph, i mean we can sketch this function on the coordinates.
02:02
First we label out of the intervals.
02:05
So 1, 1, 2, 3, 4, 5, 6, 7, 8.
02:16
Okay, so from 0 to 1, it's decreasing in concave down.
02:24
So it looks like this.
02:26
So there's a greater point, local minimum...