Answer:
Graph attached.
Step-by-step explanation:
In the question the given parameters are as followed.

1). Amplitude a = 7
2). Period = 
3). Vertical shift = 1 means mid line of the graph will be y =1 and maximum of the graph is 8 and minimum is -6.
P = 2m + 2w
Add -2w on both sides of the equations
2m = p - 2w
Divide both sides by 2
2w = p = 2m
/ 2 /2
m = 1 / 2 p - w
Answer:
Step-by-step explanation:
You could better find the answer at
https://answers.yahoo.com/question/index?qid=20110628190101AAKUGSE
where someone else has already figured it out
Answer:
6 < x ≤ 20
Step-by-step explanation:
First, let's use the points (0, 50) and (20, 0) to find the equation of the line.
m = Δy / Δx
m = (0 − 50) / (20 − 0)
m = -2.5
y = -2.5x + 50
Now find the time when y = 35.
35 = -2.5x + 50
-15 = -2.5x
x = 6
So there is less than 35 gallons in the barrel when 6 < x ≤ 20.