Question 1013926
A sound wave is modeled with the equation y = 1/4 cos 2 pi/3 theta 

a. Find the period. Explain your method.
Clarify the argument of the cosine.
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b. Find the amplitude. Explain your method.
Amp = 1/4
It's the multiplier.
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c. What is the equation of the midline?  
y = 0
What does it represent?
The neutral position.