Sound source A is located at x = 0, y = 0, and sound source B is located at x = 0, y = 2.3 m. The two sources radiate coherently
and in phase. An observer at x = 17.8 m, y = 0 notes that as he takes a few steps from y = 0 in either the +y or −y direction, the sound intensity increases. What is then the lowest frequency and next to lowest frequency of the sources that can account for this observation? (Enter your answers from smallest to largest.)
