Jika f (x) =3x+1 dan g (x) =x2+1 maka (fog) (-3)

f(x) = 3x + 1 dan
g(x) = x² + 1

maka
g(-3)
= (-3)² + 1
= 9 + 1
= 10

dan
f(10) = 3(10) + 1 = 31

jadi
(fog)(-3)
= f(g(-3))
= f(10)
= 31