Jika f(x) = 6x+2 dan g(x) = x²+4x-1 maka (fog)(4)

f(x) = 6x + 2
g(x)= x^2 + 4x - 1

(fog)(4)= f(g4)= f(4^2 + 4(4) -1) = f(31) = 6(31) + 2 = 188

Bab Fungsi Komposisi
Matematika SMA Kelas X

(fog) (x) = f(x² + 4x - 1)
(fog) (x) = 6 (x² + 4x - 1) + 2
(fog) (x) = 6x² + 24x - 6 + 2
(fog) (x) = 6x² + 24x - 4

(fog) (4) = 6 . 4² + 24 . 4 - 4
              = 6 . 16 + 96 - 4
              = 96 + 96 - 4
              = 188