This is because of the rule regarding the identity of inverse functions. No matter what an inverse function is, when you make a composite function with an original and it's inverse, then end result is always that y = x. Therefore, no matter what we put in for x (in this case 2), we get out for y.
The domain is all of the x values given listed in order from least to greatest and not repeating any numbers. The range is the same thing, but with the y values given. This is not a function because multiple ordered pairs have more than one output for the input. Let's take -2 in these ordered pairs. It has two different outputs, 3 and 2. Because of this, it is not a function.
A- positive B-negative C-positive A was positive because 5-2 would be positive 3. B was negative because 8-12 would be negative 4. C was positive because -5+8 is positive 3.