Diketahui fungsi f (x) = 2x + 1 dan ( fog ) ( x+1 ) = -2 x^2 - 4 x - 1 tentukan nilai g ( -2 ) !

(fog)(x+1) = -2x²-4x-1
misalkan x+1 = y, x = y-1
sehingga
(fog)(y) = -2(y-1)² - 4(y-1) - 1
(fog)(y) = -2(y²-2y+1) - 4y + 4 -1
(fog)(y) = -2y² + 4y - 2 - 4y + 4 -1
(fog)(y) = -2y² + 1
(fog)(x) = -2x² + 1

(fog)(x) = -2x² + 1
2(g(x)) + 1 = -2x² + 1
2(g(x)) = -2x²
g(x) = -x²
∴g(-2) = -(-2)² = 4

semoga membantu :)