<span><span>470-390=80
80/2=40
The wind is 40 mph
What does find the speed of the wind in still air mean? The wind is not still air!
Do you mean find the speed of the wind or find the speed of the plane in still air? Try reading your post before clicking submit.
470-40=430
390+40=430
The plane in still air goes 430 mph
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The answer is AAAAAAAAAAAAAAAA
Answer: D
Step-by-step explanation: 
Answer:
4π
Step-by-step explanation:
This is a sinusoidal function.
The period of the function is basically the length from one wave crest to the next crest. We can take any 2 subsequent crests.
Lets take our first crest to be at 3π
The next one will be at 7π, as we can see
So, the length from one crest to the next is the period, which is:
7π - 3π
= 4π
Third answer choice is right, 4π is the period.
