Diketahui f:R-->R f(×) = 2×+4/ 2×+4 , x tidak sama dengan 1/2 Ditanyakan: nilai f^-1 (2)

f(x) = 2x+4/2x+4, x ≠ -1/2
y = 2x+4/2x+4
y(2x + 4) = 2x + 4
2xy + 4y = 2x + 4
2xy - 2x = 4 - 4y
x (2y - 2) = 4 - 4y
x = 4 - 4y/2y - 2
f^-1 (x) = 4 - 4x/2x - 2
f^-1 (2) = 4 - 4(2)/2(2) - 2
= 4 - 8/4 - 2
= -4/2
= -2