Answer:
Step-by-step explanation:
The height of the marshmallow (in feet) is represented by the equation h=−16t2+8t+48,
where t is the time (in seconds) after he throws the marshmallow.
The equation is a quadratic equation. When the marshmallow hits the ground, its height from the ground will be zero. Therefore
−16t^2+8t+48 = 0
- 2t^2 + t + 6 = 0
Multiplying through by the negative sign. It becomes
2t^2 - t - 6 = 0
2t^2 + 3t - 4t - 6 = 0
t(2t + 3) - 2(2t + 3) = 0
(t - 2)(2t + 3) = 0
t - 2 = 0 or 2t + 3 = 0
t = 2 or t = - 3/2
The time cannot be negative
So it will take 2 seconds to hit the ground
