If you need help visualizing this, you might draw vertical lines at distance = 1 and at distance = 5. Look at the points where those lines cross f(x). The vertical difference is perhaps 350 ft. Look at where the lines cross g(x). That vertical distance may be about 200 ft.
The vertical change from 1 to 5 is considerably less for g(x) than for f(x).
Tory should choose path ...
g(x)