00:01
In this problem, we're told that in the investment, it's initially worth $9 ,000.
00:04
So we want to write a formula to find the value of the investment for each of the following descriptions.
00:10
So the first one we have is the value is going to increase by 7 % per year.
00:15
Well, in this case, we're going to use an exponential model.
00:17
So our model is going to be for our function v of t is going to equal to z sub -zero, the initial amount, times 1 plus r, which is our rate, all raised to the t power because it's happening per year.
00:30
Well, in this case, our initial investment is 9 ,000, so that's v -0.
00:34
R is our rate.
00:36
But remember, we need our rate is a decimal, so we move to the decimal point two places to the left.
00:40
So have 1 plus 0 .07, all raised to the t power.
00:44
Well, 1 plus 0 .07 is 1 .07.
00:47
So our function would be v t equals 9 ,000 times 1 .07 raised to the t power.
00:55
So that's the answer to the part a.
00:56
Now, for part b, again, it's going to increase by 7%, but it's only going to do this every three years.
01:05
So the initial part is going to stay the same...