
Randall S. answered 09/25/20
Experienced HS/college math tutor
i suspect your table is not visually represented the way you see it in the original problem.
whenever you get an x value, the y (or f(x)) that corresponds to it tell you what you want to know. they tell you an x, then the f(x) is the corresponding y that goes with your given x. if they ask what is f(8), find 8 in the x's and the corresponding y is your answer.
if they ask f-1(4), then you find 4 in the y's, and your answer is the corresponding x.