00:01
So in this problem, we're given this graph of the level or the volume of water in a swimming pool on these five days.
00:10
It's this blue line here and the volumes in thousands of gallons, as we can see.
00:16
And so first of all, we're asked to estimate the initial and final amounts of water contained in the pool.
00:21
So the initial amount will be this point here.
00:28
So that's 50 ,000.
00:35
The final amount will be here, which is on that line, so that's 30 ,000 gallons.
00:55
Okay.
00:57
Then we're asked, when did the amount of water remain constant? well, in other words, when was it horizontal or flat? so it's flat here, and it's flat here, right, horizontal there and there.
01:18
So we could say on 0 is less than or equal to x is less than equal to 1.
01:26
In other words, that first day there, period.
01:29
And from 3 is less than equal to x is less than equal to 4...