00:01
The function c of x equals 540x over 100 minus x, where x is greater than or equal to zero and less than 100, relates the cost to c in thousands of dollars to remove x percent of air pollutants for a company that burns coal to generate electricity.
00:14
First, we want to show that the cost of removing 40 percent of pollutants would be 360 ,000, and we're going to compute the cost in dollars to remove 50, 55, 60, 65, 70, 75, 80, 85, 80, 85, and 90, and 95 percent of pollutants.
00:29
Make a table of these results and make a scatter plot of the points.
00:33
So first, let's show that the cost of removing 40 % gives $36 ,000.
00:38
So that means we would just figure out c of 40.
00:41
We would let x be 40, since that represents the percent.
00:45
So that would just be 540 times 40 over 100 minus 40.
00:51
And if we do 540 times 40, 540 times 40, that gives 21.
01:00
Thousand six hundred divided by one hundred minus forty is sixty so if we do 21 ,600 divided by sixty that gives us three hundred and six and since it told us that the cost was in thousands of dollars we would just multiply that by a thousand so that would give us thirty six thousand dollars okay next we want to make this table showing the cost to make all these percentages here.
01:35
So we'll let this be x and this is the cost.
01:40
So we need to plug in 50, 55, 60, 65, 70, 75, 80, 80, 85, 80, 85, and 95.
01:53
And we need to keep in mind that this cost is in thousands of dollars, and thousands of dollars so if we plug in 50 we actually get 540 if we plug in 55 we would get 660 if we plug in 60 we get 810 65 gives us 1 ,0 .9 70 gives us 1 ,260 75 gives us 1 ,620 80 gives us 20, 80 gives us 20 or 2 ,160, 85 gives us 3 ,060, 90 gives us 4 ,860, and 95 gives us 10 ,260.
02:41
So let's plot all these points in a scatter plot, and we're going to use desmos .com to do that.
02:49
So i'm just going to plug all those points in here.
02:51
So i've got this zoomed out and those points plugged in.
02:54
I've got my x window go from like 0 to 110, and then my y's go.
03:01
From like zero to about a little over 10 ,000 there.
03:05
So we can see all those data points now.
03:10
And we can see that it's definitely increasing.
03:12
Look like it's the further we go, the more increases between each percent increase.
03:18
So this is getting steeper and steeper, definitely increasing.
03:21
Okay, the next part we want to do is we want to find the increased cost in dollar for the company to increase the amount of pollutants removed from 50 to 60 percent.
03:31
So they were just to move from 50 to 60%.
03:39
That would increase the cost from 540 to 8 .10.
03:43
So that increase in cost would just be 8 .10 minus 540.
03:47
And remember, those are in thousands.
03:49
So if we just do 810 minus 540, that would give us 270.
03:53
So 270k ,000.
03:58
And then to go from 60 to 70, to go from 60 to 70, that's 1260 minus 810.
04:08
If we do that, that's a $450 ,000 increase.
04:15
If we go from 70 to 80, that's 1 ,260 to 2160.
04:22
So that would be 2 ,160 minus 1 ,260.
04:30
And that gives about 900 ,000.
04:37
And then to go from 80 to 90%, that's going from 4860 minus 2 ,160.
04:47
And that would give us 27 ,000.
04:53
Thousand so we can see that these increases actually increase for the first increase we just went up 270 ,000 then we went up 450 ,000 so that actually is why the graph gets steeper those increases are getting further apart those points from one each since we're going up by 10 % we can see we're going up more and more each time it's not a constant increase.
05:25
Okay, according to the function c of x, is it possible to remove 100 % of the air pollutants? so that function c of x was 540x over 100 minus x...