Two rays traveling parallel to the principal axis strike a large plano-convex lens having a refractive index of 1.60. If the convex face is spherical, a ray near the edge does not pass through the focal point (spherical aberration occurs). Assume this face has a radius of curvature of R = 20.0 cm and the two rays are at distances h₁=0.500cm and h₂=12.0cm from the principal axis. Find the difference Δx in the positions where each crosses the principal axis.