If we know that f(-4) = 8, then what (x, y) point must lie on the graph y = f(x)?.
The point is (-4, 8)
For a given function y = f(x), all the points (x, y) on the graph are of the form:
(x, y) = (x, f(x))
So if we know that:
f(-4) = 8
Then we know that the point:
(-4, f(-4)) = (-4, 8)
Must lie on the graph of y = f(x)
Then the correct answer is (-4, 8)
If you want to learn more, you can read:
Answer: Club A
EXPLANATION
Given,
Club A charges $12 for membership and $2 for each rented video.
The deal in Club A can be represented by the function, f(x) = 12 + 2x
Club B charges $4 for membership fee and charges $4 for each rented video.
The deal in Club B can be represented by the function, f(x) = 4 + 4x
To determine which video rental club is the better deal
First, we find the number of videos where the amount spent will be the same
That is, when 4 + 4x = 12 + 2x
Subtract 4 from both sides of the equation
4 + 4x – 4 = 12 + 2x – 4
4x = 8 + 2x
Subtract 2x from both sides of the equation
4x – 2x = 8 + 2x – 2x
2x = 8
Divide both sides by 2
2x/2 = 8/2
x = 4
Since the deals for club B and club B will be of equal expense by the time a total of 4 videos have been rented, the better deal is the one that is cheaper when more than 4 videos have been rented.
Take a random value of x that is greater than 4, say 6
For the deal in Club A, f(x) = 12 + 2x
= 12 + 2(6)
= 12 + 12
= $24
For the deal in Club A, f(x) = 4 + 4x
= 4 + 4(6)
= 4 + 24
= $28
Since the deal in Club A is cheaper on the long run (i.e for 5 videos and above), it is a better deal than that of Club B