Question

3 function f gives the distance of a dog from a post, in feet, as a function of time, in seconds, since its owner left.
find the value of f(20) and of f(140).
4 function c gives the cost, in dollars, of buying n apples. what does each expression or equation represent in this situation?
a. c(5) = 4.50
b. c(2)

Explanation:

Problem 3:

Step1: Find \( f(20) \)

To find \( f(20) \), we look at the graph of the function \( f \) where the \( x \)-value (time) is 20 seconds. From the graph, when \( x = 20 \), the corresponding \( y \)-value (distance) is 3 feet. So, \( f(20)=3 \).

Step2: Find \( f(140) \)

To find \( f(140) \), we look at the graph of the function \( f \) where the \( x \)-value (time) is 140 seconds. From the graph, when \( x = 140 \), the corresponding \( y \)-value (distance) is 4 feet (since the peak around \( x = 140 \) reaches 4 feet). So, \( f(140)=4 \).

The function \( C(n) \) represents the cost (in dollars) of buying \( n \) apples. So, \( C(5) \) means we are evaluating the function at \( n = 5 \), which represents the cost of buying 5 apples. The equation \( C(5)=4.50 \) means that the cost of buying 5 apples is 4.50 dollars.

Part (b): \( C(2) \)

The function \( C(n) \) gives the cost (in dollars) of buying \( n \) apples. So, \( C(2) \) represents the cost (in dollars) of buying 2 apples.

Answer:

\( f(20) = 3 \) and \( f(140) = 4 \)

Problem 4:

Part (a): \( C(5)=4.50 \)