(9 + sqrt(97))/8 C is the closest answer - probably just ignore the fact that - will give a negative result
Answer:
it takes 2.4 seconds for the football to hit the ground
Step-by-step explanation:
h = −16t^2 + 36t + 4
When the ball reaches the ground the height becomes 0
so we replace h with 0
0 = −16t^2 + 36t + 4
Apply quadratic formula to solve for t
[tex]t=\frac{-b+-\sqrt{b^2-4ac} }{2a}[/tex]
a= -16, b= 36 and c= 4
[tex]t=\frac{-36+-\sqrt{36^2-4(-16)(4)}}{2(-16)}[/tex]
[tex]t=\frac{-36+-\sqrt{1552}}{-32}[/tex]
[tex]t=\frac{-36+-4\sqrt{97}}{-32}[/tex]
[tex]t=\frac{9+-\sqrt{97}}{8}[/tex]
t= -0.106 and t= 2.356
time t cannot be negative
so it takes 2.4 seconds for the football to hit the ground
