Question

A plane travels 2,000 kilometers at a speed of 900 kilometers per hour (kph) with no wind. When a tailwind is present, the plane’s speed increases by x kilometers per hour. The time it takes the plane to travel the same distance with the tailwind, t(x), is defined by the function . What is the meaning of the y-intercept for this function?

the time it takes the plane to travel without the tailwind
the speed of the plane when there is no tailwind present
the minimum amount of time it takes the plane to travel 2,000 km
the time it takes the plane to travel when the speed is decreased by 900 kph

Answer 1

t(x) = 2000/(900 + x). The y‑intercept is t(0) = 2000/900 = 20/9 hours, which is the time to travel 2,000 km with no tailwind. So the correct choice is: "the time it takes the plane to travel without the tailwind."