Question

Let X = {1, 2, 3, 4} and Y = {1, 5, 9, 11, 15, 16}
Determine which of the set are functions from X to Y.

(c) f₃ = {(1, 5), (2, 9), (3, 1), (4, 5), (2, 11)}

 

 

Answer 1

(c) Given:
f₃ = {(1, 5), (2, 9), (3, 1), (4, 5), (2, 11)}
f₃ is not a function from X to Y because 2 ∈ X has two images, 9 and 11, in Y.