Answer the following questions for each of the relations below
1: Find two sets A and B and a function f : A → B that is injective but not surjective.
2: Find two sets A and B and a function f : A → B that is surjective but not injective.
Now consider the four relations shown here:
For each relation, answer the following two questions.
3: Is it a function?
4: If not, why not? If so, is it injective, surjective, both, or neither?
In earlier versions of the text the questions were in a different order [ 3, 4, 1, 2].