jika f(x)=x-6 dan g(x)=x²-2x-24 tentukan (G o F)(5)

f(x) = x - 6
g(x) = x² - 2x - 24

Penyelesaian

g o f (x) = g(f(x)) = g(x - 6)
g o f (x) = (x - 6)² - 2(x - 6) - 24
g o f (x) = x² - 12x + 36 - 2x + 12 - 24
g o f (x) = x² - 14x + 24

Jadi, g o f (5) adalah

g o f (5) = 5² - 14(5) + 24
g o f (5) = 25 - 70 + 24
g o f (5) = -21

(G°F)=(x-6)^2-2(x-6)-24
=(x²-12x+36)-2x+12-24
=x²-12x+36-2x+12-24
=x²-14x+24
(G°F)(5)=5²-14•5-24
=25-70+24
=-21