The function h(t) = -16t² + 72t will equal zero when the ball hits the ground:
-16t² + 72t = 0. Solving for the time, t, we factor -16t² + 72t : 16t (-t + 4.5) = 0.
This results in t = 0 and t = 4.5 sec. The ball hits the ground after 4.5 sec.
Problem 12.
Starting with A:(-5,3): Reflecting A over the y-axis results in B: (5,3). Translating B 3 units to the right results in C: (8,3). Finally, translating C down by 4 units results in D: (8,-1) (answer).