Let a and b be two complex numbers with b 0. Consider the function f(z) za bz - 1 defined on the set D = C\ {}. Suppose 1, -1, E D and |f(1) = f(-1) | = |f(i) | = 1. (1) Show that ba and f(z) = 1 for all z ED with Iz | = 1. (ii) Show that f(z) is a constant function if la = 1.