Answer:
7. B 8. C 9. C
Step-by-step explanation:
7. y is greater than because the area above the line is shaded and since the line is dashed there it's not greater than or equal to.
8. C provides the correct y values for all of the x values.
9. The point (6, 3) produces -3 ≥ -8 which is the only one that is correct out of all the points provided.
Amplitude: 4
If midline means center, it is -5
I'm also implying that there is an x in cos(4x)
Equation of a line:

m = gradient: The difference between two y points and two x points.

c = y-intercept: Where the line crosses the y-axis (x=0)
You have:

so you are missing the m and the c.
To calculate m find two y coordinates -you have (12,
<u>7</u>) and (0, <u>
1</u>)- and subtract them. Then divide this by the subtracted values of the x coordinates -you have (<u>
12</u>, 7) and (<u>
0</u>, 1)- This gives:



To calculate the c, you just see where the line crosses the y-axis. Because you have the point (0, 1), you know that when x=0, y=1. Because x=0 is on the y-axis, you can tell that the line passes through y=1. This makes your c = 1:

When you plug these values into the equation you get your answer:
Answer:
41
Step-by-step explanation: