49. A thin-film coating with a refractive index of 1.39 is used on a camera lens that has a refractive index of 1.47 to cancel out reflected light with a wavelength of 5.40 X 10 m. (10.1) T/I (a) Calculate the minimum thickness for the coating that will accomplish this anti-reflection. (b) The manufacturers report that they cannot apply a coating this thin. Determine the next two possible thicknesses that will also accomplish this anti-reflection