It would be 9!!!
Hope that helps!!!
Answer:
The equation is given by:

Step-by-step explanation:
Sine function:
Has the following format:

In which A is the amplitude and
is the period.
Suppose you know the temperature is 80 degrees at midnight and the high and low temperature during the day are 89 and 71 degrees
This means that the amplitude of the sinusoidal variation function is 89 - 80 = 80 - 71 = 9. This means that 
During a 24-hour day, which means that the period is 24. So




So the variation is:

Assuming t is the number of hours since midnight, find an equation for the temperature, D, in terms of t.
Initial temperature of 80, so:

I believe the answer to be only sequence A.
-Hope this helps, have a nice day! :)
Answer:
She can walk 2.46 repeating miles in 1 hour
Step-by-step explanation:
We can write a proportion to solve this problem. Write the number of miles on top and the time in minutes on the bottom. We know 1 hour is 60 minutes.
1.85 miles x miles
------------------- = ----------------------
45 miles 60 minutes
Using cross products
1.85 * 60 = 45x
Divide each side by 45
1.85*60/45 = 45x/45
2.466666666 =x
She can walk 2.46 repeating miles in 1 hour