The amount of money in an account may increase due to rising stock prices and decrease due to falling stock prices. Marco is studying the change in the amount of money in two accounts, A and B, over time.

The amount f(x), in dollars, in account A after x years is represented by the function below:

f(x) = 1,264(1.09)x

Part A: Is the amount of money in account A increasing or decreasing and by what percentage per year? Justify your answer. (5 points)

Part B: The table below shows the amount g(r), in dollars, of money in account B after r years:

r (number of years) 1 2 3 4
g(r) (amount in dollars) 1,375 1,512.50 1,663.75 1,830.13


Which account recorded a greater percentage change in amount of money over the previous year? Justify your answer. (5 points)

Respuesta :

Exponential functions can either represent growth or decay.

Part A:

The function is given as:

[tex]f(x) = 1264(1.09)^x[/tex]

The above function is an exponential function.

An exponential function is represented as:

[tex]f(x) = ab^x[/tex]

Where b represents the rate.

When b > 1, then the function is increasing

By comparison:

[tex]b = 1.09[/tex]

1.09 is greater than 1

Hence, the amount of money in account A is increasing.

Part B:

Divide any two concurrent values on the table, to determine the rate of the table.

So, we have:

[tex]b = \frac{1512.50}{1375}[/tex]

[tex]b = 1.10[/tex]

By comparison:

1.10 is greater than 1.09 (the rate of account A).

Hence, account B records a greater percentage change in the amount of money

Read more about exponential functions at:

https://brainly.com/question/11464095