Hi guys, Couldn't figure this question out even after some thinking through. Hope someone can help me here. 2 loudspeakers are placed 1.2m vetrically apart. The point A is the horizontal distance of 1.6m from the top speaker. Both speakers are operating in phase with a steady freq of 400Hz and the speed of sound can be assumed to be at 320ms^-1. Does point A have maximum/minimum/somewhere between max and min intensity? The answer I was given is minimum intensity. I used the formula y = (lambda)D/a where D = 1.6 and a = 1.2 and y = fringe spacing. I worked y out to be 1.067m which I interpret this result as a bright fringe 1.067m above the central maximum. I then used inverse tangent of 0.6/1.6 and sin the resultant angle multiplied by 1.2, to find the path difference. Am I correct till here? How should I continue to find whether if the 2 waves are in phase to point A?