Question

Fungsi f(x) dan g(x) didefinisikan dengan f(x) = x2, g (x) = 1 - 2x, dan (fog)(a) = 25. Nilai a =

Answer 1

Fog (x) = (-2x+1)(-2x+1)

Fog (x) = 4x²-4x+1

Fog (a) = 25

Jadi :

4a²-4a + 1 = 25

4a²-4a - 24 = 0

a² - a - 6 = 0

(a+2) (a-3) = 0

a = -2 atau a = 3