A sound wave is modeled with the equation (shown in comments)

a. Find the period. Explain your method.
b. Find the amplitude. Explain your method.

Question

A sound wave is modeled with the equation (shown in comments)

a. Find the period. Explain your method.
b. Find the amplitude. Explain your method.

anonymous · Answer

$$y=\frac{ 1 }{ 4 }\cos \frac{ 2\pi }{ 3 }\theta$$

kropot72 · Answer

The period is given by
$$T=\frac{2 \pi}{\frac{2 \pi}{3}}$$

anonymous · Answer

It still does't make sense...

anonymous · Answer

We begin with Acos(Bx) right?

kropot72 · Answer

The period is given by 2*pi divided by the coefficient of the angle theta.
The general equation is
$$y=A \cos(B\  \theta)$$
where |A| is the amplitude
and the period is
$$T=\frac{2 \pi}{B}$$

kropot72 · Answer

In your question
$$B=\frac{2 \pi}{3}$$

anonymous · Answer

It wasn't making sense at first, but then I watched this YouTube video, https://www.youtube.com/watch?v=kiuV-DAlopE, and now your explanation makes sense. Thank you!

anonymous · Answer

The amplitude would be 1/4, correct?

kropot72 · Answer

Your result for the amplitude is correct. What was your result for the period?