Answer:
f (x)= (1, 4) (2, 3) (5, 8) (4, 7)
f-1(x) = (4, 1) (3, 2) (8,5) (7,4)
For any given x in the domain of f-1(x) there is one and only
one value y in the range of f-1(x) ... Thus, f-1(x) passes the
vertical line test and is a function.
Explanation: