jika diketahui f(x)=x+4 dan g(x)=3x+1 hitunglah nilai dari (fog)^1(2) adalah

(fog)(x) = (3x+1) + 4
(fog)(x) = 3x + 5
y = 3x + 5
3x = y - 5
x = (y-5)/3
(fog)^-1(x) = (x-5)/3
(fog)^-1(2) = (2-5)/3
(fog)^-1(2) = -1