Answer:
At approximately x = 0.08 and x = 3.92.
Step-by-step explanation:
The height of the ball is modeled by the function:
Where f(x) is the height after x seconds.
We want to determine the time(s) when the ball is 10 feet in the air.
Therefore, we will set the function equal to 10 and solve for x:
Subtracting 10 from both sides:
For simplicity, divide both sides by -1:
We will use the quadratic formula. In this case a = 16, b = -64, and c = 5. Therefore:
Substitute:
Evaluate:
Simplify the square root:
Therefore:
Simplify:
Approximate:
Therefore, the ball will reach a height of 10 feet at approximately x = 0.08 and x = 3.92.