Question

A student is running a 3-kilometer race. He runs 1 kilometer every 2 minutes. Select the function that describes his distance from the finish line.

Answer 1

The function describing the student's distance from the finish line as he runs a 3-kilometer race is d(t) = 3 - 0.5t, where t is time in minutes.

Step-by-step explanation:

The function that describes the student's distance from the finish line of a 3-kilometer race, given that he runs 1 kilometer every 2 minutes, is a linear equation representing distance over time. We can express this with the function d(t) = 3 - 0.5t, where d is the distance (in kilometers) from the finish line, and t is the time (in minutes).

To derive this function, we know the student starts 3 kilometers away from the finish line, and for every two minutes that pass, the student covers 1 kilometer. Therefore, the rate of distance decrease per minute is 0.5 kilometers since 1 kilometer/2 minutes equals 0.5 kilometers per minute. We subtract this value from the initial distance to obtain the function representing the distance from the finish line over time.

Answer 2

x - number of minutes;
f ( x ) - the distance from the finish line.
x : 0 2 4 6
f ( x ) : 3 2 1 0
f ( x ) = 3 - x/2
Answer: B ) f ( x ) = -1/2 x + 3