High School

4. The equation [tex]$f(t)=24,500 \cdot(0.88)^t$[/tex] represents the value of a car, in dollars, [tex]$t$[/tex] years after it was purchased.

a. What do the numbers 24,500 and 0.88 mean?

b. What does [tex]$f(9)$[/tex] represent?

c. Sketch a graph that represents the function [tex]$f$[/tex] and shows [tex]$f(0), f(1)$[/tex], and [tex]$f(2)$[/tex].

Answer :

Sure, let's break down the solution step-by-step for each part of the question.

### Part a: Explanation of the numbers 24,500 and 0.88

- 24,500: This number represents the initial value of the car in dollars, which is the purchase price when it was first bought.
- 0.88: This number represents the annual depreciation factor of the car. In this context, it means that each year the car retains 88% of its value from the previous year. This is a percentage decrease, indicating that the car loses 12% of its value every year.

### Part b: Understanding [tex]\( f(9) \)[/tex]

- [tex]\( f(9) \)[/tex]: This expression represents the value of the car 9 years after it was purchased. Plugging into the function, we calculate the car's value as follows:

[tex]\[
f(9) = 24,500 \times (0.88)^9
\][/tex]

Calculating this gives the car's value 9 years after purchase, which is approximately [tex]$7,753.72.

### Part c: Values for the graph

To plot the graph, we need to find the car's value at specific times.

- \( f(0) \): This is the starting value when the car was just purchased.

\[
f(0) = 24,500 \times (0.88)^0 = 24,500
\]

Since anything to the power of 0 is 1, the value remains as $[/tex]24,500.

- [tex]\( f(1) \)[/tex]: This is the value of the car one year after the purchase.

[tex]\[
f(1) = 24,500 \times (0.88)^1 = 21,560
\][/tex]

- [tex]\( f(2) \)[/tex]: This is the value of the car two years after the purchase.

[tex]\[
f(2) = 24,500 \times (0.88)^2 = 18,972.80
\][/tex]

These calculations give us the points [tex]\( (0, 24,500) \)[/tex], [tex]\( (1, 21,560) \)[/tex], and [tex]\( (2, 18,972.80) \)[/tex], which can be plotted on a graph to visualize the depreciation of the car's value over time. The graph will show a downward curve, reflecting how the car loses value each year.