Question

Ali and Kris 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 their distance from home as a function of time. What is a reasonable domain for this situation?

Function notation in slope-intercept form: f(x) =
x +


A reasonable domain is
≤ x ≤
.

Answer 1

Let x = hours after now and f(x) = miles from home.

f(x) = 50x + 20

A reasonable domain is 0 ≤ x ≤ 2 (after 2 hours they reach the city at 120 miles).