It would be 1/8 I am pretty sure
9 to the 3rd power is 729
And 2 to the 5th power is 32. You multiple 9, 3 times. 9 times 9 times 9 and you multiply 2, five times. 2 times 2 times 2 times 2 times 2
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>