The formula for the location of destructive interference in the case of single slit diffraction is given by sinθdark=mλ/a where a is the opening size and \(m=0,\pm 1,\pm 2,\pm...The formula for the location of destructive interference in the case of single slit diffraction is given by sinθdark=mλ/a where a is the opening size and m=0,±1,±2,±3… where a is the width of the opening and θ is the angle to each successive dark spot, labeled with the number m.