we have the function

Part a
For t=7
substitute in the given function

For t=14

For t=21

For t=28

For t=35

Observation: The values of E varies from -1 to 1, including the zero
Part B
Remember that
The Period goes from one peak to the next
so
Period=2pi/B
B=pi/14
Period=(2pi)/(pi/14)=2pi*14/pi=28
<h2>the period is 28 days</h2>
The discount is 50-14 = $36
% discount = (36/50)*100 = 72%
-3x+7<11
-3x<4
x>-4/3
So anything less than or equal to -4/3 does not belong to the solution set.
With your update:
"<span>The options is 4,-1,-5,and 0"
-5 does not belong to the solution set...</span>
Answer: A
Step-by-step explanation: