1. The problem statement, all variables and given/known data You are L = 3 m away from a pair of speakers playing a pure tone separated by a distance of d = 1 m. If you walk from the center to a distance of y = 0.75 m, you hear the intensity decrease to zero, then increase all the way back to the initial volume. 2. Relevant equations frequency(observed) = frequency(emitted) x (1 + u/v) 3. The attempt at a solution I have no idea where to get started!