Answer:
Step-by-step explanation:
Given function is h(t) = -16t² + 1500
a). For h(t) = 1000 feet,
1000 = -16t² + 1500
1000 - 1500 = -16t² + 1500 - 1500
-500 = -16t²
t² = 
t = 
t = 5.59 sec
b). For h(t) = 940 feet,
940 = -16t² + 1500
940 - 1500 = -16t² + 1500 - 1500
-16t² = -560
t² = 
t = 
t = 5.92 sec
c). For domain and range of the function,
When the jumper comes down to the ground,
h = 0
0 =-16t² + 1500
t² = 
t = 
t = 9.68 sec
Since, x-values on the graph vary from x = 0 to x = 9.68,
Domain : [0, 9.68]
Vertex of the quadratic function: (0, 1500)
Since, coefficient of the highest degree term is negative, parabola will open downwards.
Therefore, y-values of the function will vary in the interval y = 0 to y = 1500
Range: [0, 1500]
Function:
y = -2/3 x + 7
Substitute the given values to their respective variable and solve.
x y
-6 3
3 5
15 -3
-12 15
The goal to proving identities is to transform one side into the other. We can only pick one side to transform while the other side stays the same the entire time. The general rule of thumb is to transform the more complicated side (though there may be exceptions to this guideline).
So I'll take the left hand side and try to turn it into 
One way we can do that is through the following steps:

Since we've shown that the left hand side transforms into the right hand side, this verifies the equation is an identity.
Answer:
x > 0; $1280
Step-by-step explanation:
Domain should be x > 0 because length is not negative
When x = 8
Cost = 20(8²) = 1280