Match the sets of points representing one-to-one functions with the sets of points representing their inverse functions. h = {(1,1), (2,2), (3,3), (4,4), (5,5), (6,6)} g = {(1,3), (2,6), (3,9), (4,12), (5,15), (6,18)} f = {(1,2), (2,3), (3,4), (4,5), (5,6), (6,7)} i = {(1,1), (2,3), (3,5), (4,7), (5,9), (6,11)}h-1 = {(1,1), (2,2), (3,3), (4,4), (5,5), (6,6)} i -1 = {(1,1), (3,2), (5,3), (7,4), (9,5), (11,6)} g-1 = {(3,1), (6,2), (9,3), (12,4), (15,5), (18,6)} f -1 = {(2,1), (3,2), (4,3), (5,4), (6,5), (7,6)}

The one-to-one functions given as sets of points and their possible inverse functions are given as
h   = { (1,1),  (2,2), (3,3),   (4,4),  (5,5),  (6,6)}
g   = { (1,3), (2,6), (3,9), (4,12), (5,15),  (6,18)}
f    = { (1,2), (2,3), (3,4),  (4,5),  (5,6),  (6,7)}
i    = { (1,1),  (2,3), (3,5),  (4,7),  (5,9),  (6,11)} 

h⁻¹ = { (1,1),  (2,2), (3,3),  (4,4),  (5,5),  (6,6)}
i⁻¹  = { (1,1),  (3,2), (5,3),  (7,4),  (9,5),  (11,6)}
g⁻¹ = {(3,1), (6,2), (9,3), (12,4), (15,5), (18,6)}
f⁻¹  = {(2,1), (3,2), (4,3),  (5,4),  (6,5),  (7,6)}

The inverse function of a given function should have the coordinates reversed. 
Therefore the matches between the given functions and their inverse functions are given in the table below.

function Inverse function
 
        h            h⁻¹
        g            g⁻¹
        f             f⁻¹
        i             i⁻¹

The given functions and their corresponding inverses are correct.

The answer is 8 apex