Two speakers S1 and S2 are at a distance from each other. Point Q is located at y = 2.1 m above loudspeaker S2 while point P is located at x = 4.1 m in front of loudspeaker S1. The two loudspeakers emit a sound of frequency f = 96 Hz in phase. It is assumed that the intensity does not decrease with the distance from the loudspeakers, and that the modulus of the speed of sound is 340 m/s. What is the minimum value of d for which the sound intensity is zero at each of the following points: (a) P; ?(b) Q??