A spherical surface of radius of curvature r separates a rarer and denser medium. Complete the path of the incident ray of light. Derive the relation between u, v, r, n1, and n2.

a) (n₁/u) + (n₂/v) = (n₂ - n₁)/r
b) (n₁/u) - (n₂/v) = (n₂ - n₁)/r
c) (n₁/u) + (n₂/v) = (n₁ - n₂)/r
d) (n₁/u) - (n₂/v) = (n₁ - n₂)/r