diketahui f : R → R dan g : R → R. jika f(x) = x+1 dan (fog)(x) = 4x² + 4x, tentukan g(x-2)

jawab

f(x)= x + 1
fog(x) = 4x² + 4x

f{g(x)} = 4x² + 4x
g(x) + 1 = 4x² + 4x 
g(x)= 4x² + 4x - 1

g(x-2) = 4(x -2)² + 4(x - 2) - 1
= 4(x² - 4x + 4) + 4x - 8 - 1
= 4x² -16x +16 + 4x -8- 1
= 4x² -12x  + 7