Answer:
D because those are both concerning.
Answer:
3 Cycles
Explanation:
Every cycle on a cosine function are marked by the completion of 5 key points when moving along the x-axis:
(5, 0, -5, 0, 5)
This cycle has a frequency of 2, occurring once every second, thus answering our question easily.
Answer:
The average speed for the entire run is 12 km/h.
Explanation:
The average speed is given by the following equation:

Where:
: is the total distance
: is the total time
If during the first hour, they ran a total of 13 kilometers and then, they ran 5.0 kilometers during the next half an hour we have:


Hence, the average speed is:

Therefore, the average speed for the entire run is 12 km/h.
I hope it helps you!