For destructive interference dsinθdark=(m+1/2)λ where m=0,±1,±2,±3… In both cases d is the distance between the center of the openings (the separation of the ...For destructive interference dsinθdark=(m+1/2)λ where m=0,±1,±2,±3… In both cases d is the distance between the center of the openings (the separation of the sources), the angle θ is the angle from the central maximum out to a minimum or maximum and m numbers the maximums (or minimums) starting from the center (m=0).