Jika g(x) = x + 3 dan (f g)(x) = x2 – 4, maka f(x – 2) = …

Misal :
x+3=p
x=p-3

fog(x)= x^2-4
f(x)= (p-3)^2 -4
f(x)= p^2 -6p +9 -4
f(x)= p^2 -6p +5
f(x)= x^2 -6x +5

f(x-2)= x^2 -6x +5
f(x-2)= (x-2)^2 -6(x-2) +5
= x^2 -4x +4 -6x +12 +5
= x^2 -10x +21