A light ray is traveling in air with an index of refraction of unity and it is reflected at the boundary or a second medium with an index of refraction n. Consider the optical coating on a glass lens where the index of refraction of the coating is n, where n is greater than the index of refraction of the air. Assume: The index of refraction of the lens is greater than that of the coating. To minimize the reflection of a ray with a wavelength 500nm and incident angle θ=0, what is the minimum nonzero thickness of the coating?