1. Determine whether each set is a function from X = {1, 2, 3, 4} to Y = {a,b,c,d}. If it is a function, find its domain and range and determine if it is one-to-one, onto, or both. If it is both one-to-one and onto, give the description of the inverse function as a set of ordered pairs and give the domain and range of the inverse function.

(a) {(1, a), (2, a), (3, c), (4, b)} (3 points)

(b) {(1, c), (2, a), (3, b), (4, c), (2, d)} (1 point)

(c) {(1, c), (2, d), (3, a), (4, b)} (5 points)

(d) {(1, d), (2, d), (4, a)} (1 point)

(e) {(1, b), (2, b), (3, b), (4, b)} (3 points)