Hey there
If an arrow diagram represented a function, every value in the input would go to its own unique output. In other words, one number on the left side can only go to one certain number on the right side. Now that we know this, let’s answer the questions. I will answer yes if it is a function and no if it isn’t, as well as the explanation.
a) Yes
b) No. 2 goes to both a and b.
c) Yes
d) Yes
e) Yes
f) Yes