For a refractive index () = \sin12(A+D)\sin12A D = angle of minimum deviation A = refractive angle of the prism 1.5 = \sin12(60+D)\sin12×60 1.5 = \sin12(60+D)\sin30 Sin 12 (60 + D) = 1.5 * Sin 30 Sin 12 (60 + D) = 0.75 12 (60 + D) = Sin-1 (0.75) but Sin-1 (0.75) = 49o 12 (60 + D) = 49 60 + D = 2 * 49 = 98o D = 98o - 60o D = 38o
