How do you solve this problem?

Number one here:

I got parts a) and b), but I can't get c) or d). How do you do those parts?

http://www.math.rutgers.edu/~greenfi...dfstuff/w1.pdf

I think for c), you could take an x value on A and plug it into C(x) to get points on C, but for instance, if put x=1, then C(x)=A(5), but A(5) is not in the domain of A....so this part confuses me. For d), I know we are looking for the inver, which is the reflection about y=x, but I am not sure how to draw that with this graph and what the domain and range would be.