Long before modern theories of resonances were developed, Augustin-Louis Cauchy proposed a formula for refractive index that bears his name. Cauchy's formula claims that: n=B + C/λ^2, where B and C can be experimentally determined. Note: This B and C are different from those in part a. In addition to the restrictions in part (b) above (that we are far from resonances), what additional assumptions must we make to arrive at Cauchy's formula? [Hint: Start from part (b) and find the condition for which the λ^2 term can be neglected.]