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A beam of light is incident upon a material whose dispersion coefficient is dn/d=17.9105nm1, with n0=1.500 when 0=533.0nm. If denotes the refraction angle, what is the absolute value of the angular separation of the refracted beams produced by this material if the incident beam contains wavelengths between 1=459.0nm and 2=639.0nm and the beam' angle of incidence i is 39.75 ? =