Question

Which of the following relations is not a function?

{(0, 0), (1, 0), (2, 0)}
{(-1, 3), (4, 2), (-1, 5)}
{(1, 2), (3, -5), (-1, 7)}
{(7, -1), (3, -2), (5, -2)}

Answer 1

{(-1, 3), (4, 2), (-1, 5)}

Step-by-step explanation:

I think this is the right answer and have a great day

Answer 2

Look at the 2nd answer choice.  The input -1 shows up twice, with two different outputs {3, 5}.  This is contrary to the definition of function, which states that each input has exactly one output.