Consider the following two functions: 1. f: R -> R defined by f(r) = 4 - 15.2. 2. g: R -> R defined by g(r) = 151. Prove that both f and g are one-to-one correspondences. Let f: A -> B be a one-to-one correspondence. Then, for each b ∈ B, there corresponds a unique a ∈ A such that f(a) = b. We define f^(-1): B -> A by f^(-1)(b) as the unique a such that f(a) = b.