Did I do this right?

Question

Problem:

If the following defines a one-to-one function, find its inverse. If no, write "Not one-to-one."

{(-2,4),(-1,4),(0,1),(1,-5)}
answer: Not one-to-one because of
(-2,4), (-1,4)

Answer 1

There is only one y for each x, so the original is indeed a function.
However the inverse has those two values of y for x is 4 so the inverse is indeed not a function.