F(x)= x+2 dan (gof)(x)=6-3x² maka g(x)

(gof)(x) = 6 – 3x^2
g(f(x)) = 6 – 3x^2
g(x+2) = 6 – 3x^2
g(x+2-2) = 6 – 3 . (x-2)^2
g(x) = 6 – 3 . (x^2 – 4x + 4)
g(x) = 6 – 3x^2 + 12x – 12
g(x) = -3x^2 + 12x – 6