5. If a lens has radii of curvature R = 1.1 meters and R2 = 1.2 meters and a focal length of 10 centimeters, what is the index of refraction of the lens?
5. If a lens has radii of curvature R = 1.1 meters and R2 = 1.2 meters and a focal length of 10 centimeters, what is the index of refraction of the lens?