00:02
All right, i'm going to demonstrate this one using desmos.
00:09
The profit is given to us as negative 0 .004x to the third power minus 0 .3x squared plus 600x minus 800x minus 800.
00:38
So that's what we're given.
00:44
When x is 9, what is the weekly profit? so, i just have to copy this, paste it in here, and put in 9.
01:18
There we go.
01:25
$4 ,572, and 78 cents.
01:34
What if we dropped to 8? so, same thing.
01:45
So i just have to change the 9 to 8.
01:54
Okay, that would be the new profit, but we want to know how much profit is lost, so i have to subtract these two.
02:08
457 .2 .784 minus all of that.
02:14
We would lose $594 and $2 .3, actually...