Answer:
Explanation:
I think the missing equation in your question is: h(t) = -16 
 + 16t + 480
 + 16t + 480 
Here is my answer: 
As we know that the vertex form of a parabola, y=a
 + k where(h,k) is the vertex
 + k where(h,k) is the vertex 
h(t) = -16 
 + 16t + 480
 + 16t + 480 
= -16 (
 + 480
 + 480 
= -16 
 + 484
 + 484 
So the vertex is (
 , 484)
 , 484) 
a. It take for Joseph 
 second to reach his maximum height
 second to reach his maximum height
b. The highest point that Joseph reached is the vertex of the function, it is 484 ft 
c. Joseph hit the water after how many seconds? 
<=> h(t) = 0 
<=> -16 
 + 16t + 480 = 0
 + 16t + 480 = 0
<=> t = 
 second = 6 sec
 second = 6 sec
Hope it will find you well