Two loudspeakers are placed 3.00 m apart, as shown in the figure. They emit 440 Hz sounds, in phase. A microphone is placed d = 3.10 m distant from a point midway between the two speakers, where an intensity maximum is recorded.
(a) How far must the microphone be moved to the right to find the first intensity minimum?
(b) Suppose the speakers are reconnected so that the 440 Hz sounds they emit are exactly out of phase. At what positions (how far must the microphone be moved to the right) are the intensity maximum and minimum now?