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:

![Figure](https://docs.google.com/drawings/d/e/2PACX-1vSFi8dNH3hU5j-T2ZxOR98UB-V-Ng9YOPyP9NC4SCVjEKDf_Uh2xqHIRJGAnNZPNDxQnfseseKOgmYC/pub?w=478&h=304)

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?

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In earlier versions of the text the questions were in a different order [ 3, 4, 1, 2].