The function f(x) equals the set of ordered pairs: { (0,0) , (1,2) , (2,3) , (3,4) } These ordered pairs are in the format (x,y)....so if you are finding f(x), then your answer, in this case, would be the y-coordinate that x belongs to (ie. for ordered pair (1,2) f(1) = 2.

So for this one you need to find f(2). When x=2 in the set above, then y=3 (You can see this by looking at the ordered pair (2,3)). So f(2)=3.