Answer:
part 1) 0.78 seconds
part 2) 1.74 seconds
Step-by-step explanation:
step 1
At about what time did the ball reach the maximum?
Let
h ----> the height of a ball in feet
t ---> the time in seconds
we have

This is a vertical parabola open downward (the leading coefficient is negative)
The vertex represent a maximum
so
The x-coordinate of the vertex represent the time when the ball reach the maximum
Find the vertex
Convert the equation in vertex form
Factor -16

Complete the square


Rewrite as perfect squares

The vertex is the point 
therefore
The time when the ball reach the maximum is 25/32 sec or 0.78 sec
step 2
At about what time did the ball reach the minimum?
we know that
The ball reach the minimum when the the ball reach the ground (h=0)
For h=0



square root both sides


the positive value is

Triangles add up to 180°, so the answer is 67
$98.30=5.1a+11.6
98.30-11.6=5a+11.6-11.6
86.7=5a
86.7/5=5a/5
17.34=a
So only 17 people can attend
Answer:
Step-by-step explanation:
3. the answer should be -68
5.-8.97
Answer:
lesser x: - 6
greater x: 2
Step-by-step explanation:
f(x) = (x + 2)² – 16
(x + 2)² – 16 = 0
(x + 2 + 4) (x + 2 - 4) = 0
(x + 6)(x - 2) = 0
roots (zero): x = -6 or x = 2