Question

4. Aubrey and Charlie are driving to a city that is 120 miles from their house.

They have already traveled 20 miles, and they are driving at a constant rate
of 50 mi/h. Write a function that models the distance they drive as a
function of time. What is a reasonable domain for this situation?
Function notation in slope-intercept form: y=50x + 20
A reasonable domain is 0hr ≤x≤ 2hr.
5. Use the function you wrote in Item 4 to complete the following:
f(1.5) =__________ The value indicates that after
Aubrey and Charlie will have traveled
hours of driving,
miles.

Answer 1

f(1.5) = 50(1.5) + 20 = 85 miles. After 1.5 hours of driving, Aubrey and Charlie will have traveled 85 miles.

The domain is the set of input or the x-values that can be plugged into the function, in this case the time they spend driving. The domain is reasonable because the time cannot be negative or less than 0 and they cannot drive for more than 2 hours (as they are driving to a city that is 120 miles from their home, and they are driving at a rate of 50 miles per hour)