9. The function h(t) = 150 - 4t represents the height of a person repelling downa building for the first time where t is measured in minutes and h is measured in
feet above the ground. How high would the person be one half hour after
beginning his descent?
Half an hour is 30 minutes, so that means we are asked to find h(30).
Solve for h(30):h(30) = 150 - 4(30) Substitute 30 for th(30) = 150 - 120 Simplifyh(30) = 30
The person would be 30 feet above the ground in half an hour.
Half an hour is equivalent to 30 minutes.
Thus, h(t) = 150 - 4t becomes h(30 min) = 150 ft - 4(ft/min)(30 min) = 30 ft