jika (9°f)(x) = 4x²+4x dan 9(x) = x²-1; maka nilai dari f (x-2)

(gof)(x) = g(f(x))

4x²+4x = (f(x))² - 1

4x²+4x + 1 = (f(x))²

(2x +1).(2x + 1) = (f(x))²

(2x + 1)² = (f(x))²

√(2x + 1)² = f(x)

2x + 1 = f (x)

maka

f(x-2) = 2(x-2) + 1 = 2x - 4 + 1 = 2x - 3