The function above models the height, y, in feet of a stone t seconds after it is dropped from the edge of a vertical cliff. How long will it take the stone to hit the ground? Round to the nearest hundredth of a second

Answer:
3.94 seconds
Step-by-step explanation:
h = - 16t² + 248
If stone is dropped, then h = 0
- 16t² + 248 = 0
t² = [tex]\frac{248}{16}[/tex]
t = ± [tex]\frac{2\sqrt{62} }{4}[/tex]
t < 0 is a solution of equation, but not a solution of the task
t = [tex]\frac{2\sqrt{62} }{4}[/tex] ≈ 3.94 seconds