00:01
In this problem, we're given a table where one column is the year, and the other column is the amount of carbon dioxide emissions in that year in millions of metric tons.
00:10
In part a, we're asked to plot the data where t is the number of years since 1900.
00:19
So, for example, the year 1900 is going to correspond to t equals zero because no years have passed since 1900.
00:28
So let's go ahead and get our graph here.
00:34
So on this axis, so here's t equals zero, and then let's do 10, 20, 30, 40, 50, 50, 60, 70, 80, 90, 90, 100, and then 110.
00:49
And on this axis, let's go up to 10 ,000.
00:54
So let's say, 2 ,000, 4 ,000, 6 ,000, 8 ,000, 10 ,000.
01:02
So at t equals 0 in the year 1900, there's 500 and 34 ,000.
01:08
A million of metric tons of emissions.
01:11
So 500 is going to be about right there.
01:14
And then this jumps to 819 in the next year, or in 1910 when t equals 10.
01:20
At t equals 20, we're at 932.
01:24
In 1930, t equals 30, that's 1 ,053.
01:31
And then 1940 is 1 ,299.
01:35
So again, we're still kind of below the 2000 mark.
01:38
In 1950, t equals 50, we get 1 ,630, so we're still below the 2 ,000 mark.
01:47
But now we jump above the 2 ,000 mark in 1960, at t equals 60, it's 2 ,500.
01:54
And then in 1970, it jumps to 4 ,000, 4 ,053, so a big jump.
02:02
At t equals 80, oh, i forgot to do one mark, sorry.
02:10
This is actually, sorry about that.
02:13
This is 90.
02:14
And this is going to be 100 and 110.
02:17
Oops.
02:19
Okay, let's keep going.
02:20
So at t equals 80, we're at 1980.
02:24
So that's 5 ,315.
02:29
Oh, sorry, wrong color.
02:34
And then 1990, we're at 6 ,127.
02:38
So we're above 6 ,000 now.
02:42
And then 6 ,765.
02:46
And then finally, at t equals 110, we're at 9 ,167.
02:53
So if we look at this graph, it looks like the data is growing exponentially because we kind of have a curve here.
03:03
So our graph is kind of following this curve.
03:07
It's not following a line, right? so a linear graph would just be a line, but it's not following a line.
03:12
It looks like it's following a curve.
03:15
So we're going to guess that the data is growing exponentially.
03:20
In part b, we're going to find an exponential function to fit the data.
03:24
So our exponential function is going to be of the form f sub 0 times a to the t.
03:30
And we're going to use the data from 1990 in 2010.
03:34
So in 1990, that's t equals 0.
03:39
So f of 0 should be the number of emissions in 19, sorry, 1900, not 1990, sorry, f of 0 should be 534, because when t equals 0, there were 534 million metric tons of emissions.
03:56
In the year 2010, that's when t is 110.
04:00
It's 110 years of past since 1900.
04:03
And in the table, we see that f of 110 should be equal to 9 ,167, because that's the amount of emissions in the year 2010.
04:14
So let's use this data to solve for our f0 and our a.
04:19
So let's start with this first one.
04:21
So f of 0 is 534...