Answer:
5 seconds
1220 ft
Step-by-step explanation:
Step 1: Know when the stone reaches the maximum height
We know the maximum or minimum height of a parabola is at the vertex so we need to find the vertex
Step 2: Calculate the vertex
The t coordinate of the vertex can be calculated with 
b = 160
a = 16

Step 3: We know the t coordinate we can find the height at that time

Therefore the stone reaches its maximum height of 1220 ft in 5 secs
 
        
             
        
        
        
compare to the correct answer on the picture. If not helped you can use a graph calculator and it should let you know wether or not you’re correct
 
        
             
        
        
        
Answer:
True
Step-by-step explanation:

 
        
             
        
        
        
Answer:
f(8)=-31
Step-by-step explanation:
since 8 replaces x in f(x), x should be substituted as 8 in the expression. From there, after you substitute, it becomes 6(1-8)+11. Simplifying that expression is now 6(-7)+11. Multiply 6 and -7, you get -42. -42+11=-31. I hope this helps :)
 
        
             
        
        
        
Answer:
eastern
Step-by-step explanation: