1. The problem statement, all variables and given/known data

Two loudspeakers are placed beside each other and produce sound of the same intensity at the position of a listener. One speaker produces a low note of 40 Hz and the other produces a high note of 2560 Hz. What is the ratio of the maximum displacements of the speakers vibrating cones?

2. Relevant equations

1) $I$=P/4piR^2
2) I=1/2BωkA^2
3) I=1/2$\sqrt{ρB}$ω^2A^2

3. The attempt at a solution
I understand that I am supposed to use equation 3 for both frequencies and set them equal to each other to come up with a ratio. I just don’t understand how equation 3 is derived from equation 1, or how equation 2 is derived from equation 1 for that matter. If I could see how to manipulate these equations I would understand this type of problem much better. (The only equation I am given on my equation sheet is the first one).

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