diketahui f dan g fungsi pada bilangan real f (×)=×-2 dan g (×)=4×-3.jika (gof)-1(×)=2,maka nilai x yang memenuhi adalah

(gof)(x) = 4(x - 2) - 3
(gof)(x) = 4x - 11
y = 4x - 11
4x = y + 11
x = (y +11)/4
(gof)^-1(x) = (x + 11)/4
2 = (x + 11)/4
8 = x + 11
x = -3

f(x) = x - 2
g(x) = 4x - 3
(g○f)(x) = g○(f(x))
= g○(x - 2)
= 4(x - 2) - 3
= 4x - 8 - 3
= 4x - 11
(g○f)(x) = 4x - 11
y = 4x - 11
4x = y + 11
x = (y + 11)/4
(g○f)^-1 (x) = (x + 11)/4
(g○f)^-1 (x) = (x + 11)/4 = 2
x + 11 = 2 × 4
x + 11 = 8
x = 8 - 11
x = -3
jadi nilai x yang memenuhi adalah -3
=> (g○f)^-1 (x) = (x + 11)/4
=> (g○f)^-1 (-3) = (-3 + 11)/4
= 8/4
= 2
(TERBUKTI)