9.1-9.2, due on October 22

What was the most difficult part of the material for you?
For a minute I didn't understand the difference between a codomain and a range. A codomain is the set of objects that could be in the range (like all real numbers for f(x)=x^2).

What was the most interesting part of the material for you?
It's cool to think about the set of all functions from one set to another. Usually when we talk about functions we talk about functions with infinite domains. But when the domain and codomain are finite, it actually does make sense to talk about this, and talk about the length of it as well.