Question

The domain of the following relation: R {(6, -2), (1, 2), (-3, -4), (-3, 2)} is

Answer 1

The domain is the set of possible inputs, i.e. the x-coordinates of the points.

Here those are 6, 1 and - 3 which in order is -3, 1, 6.

Then the answer is {-3, 1, 6}.

By the way note that this relation is not a function. Do you know why?

Because the image of -3 is not stated unambiguosly.