Answer:
f(x)=-1/2x+3
Step-by-step explanation:
In this problem, the student is running a 3-kilometer race.
This means that the total length of the race is 3 km.
We also know that the student runs 1 kilometer every 2 minutes. For a uniform motion, the speed is given by
where in this case,
d = 1 km is the distance
t = 2 min is the time
So the speed is
We can therefore write the distance covered by the student (from the starting line) after x minutes as
However, here we want to write an expression for the distance of the student from the finish line.
Since the distance from the finish line at x = 0 is 3, therefore the distance from the finish line after x minutes is:
d = 3 - y'
So
which corresponds to the option:
f(x)=-1/2x+3