Answer:
11 km/hr.
Step-by-step explanation:
Given information:
Simulated speed = 20/km/h
Time = 15 mins = 1/4 hr = 0.25 hr
Distance Covered as per simulated speed = 
Position of Julian according to the app =
.
Actual distance covered by the bike is

Formula for speed:



Therefore, the average speed of Julian is 11 km/hr.
<h2>
Answer:</h2>

<h2>
Step-by-step explanation:</h2>
The graphs of
can be obtained from the graph of the cosine function using the reciprocal identity, so:

But in this problem, the graph stands for the function:

Because the period is now 4π as indicated and for
in the figure and this can be proven as follows:

Also,
as indicated in the figure and this can be proven as:
