tolonginnnnn (g°f) (x) = 2x(kuadrat)-4x-1 f(x). = x-2 g(x). = ....?

jawab

gof(x) = 2x² - 4x - 1
f(x) = x- 2

g{f(x)} = 2x²-  4x -1
g(x-2 ) = 2x² - 4x - 1
x-2= y
x = y + 2

g(y) = 2(y+2)² - 4(y+2) -1
g(y) = 2(y²+4y +2) - 4y -8 - 1
g(y) = 2y² +8y + 4 -4y -8 -1
g(y) = 2y² + 4y - 5
g(x) = 2x² + 4x - 5