f(x)=x+3 dan g(x)=x²-2x+5,maka(g•f)(x)=

(g•f)(x) = g (x+3)
= (x+3)^2 - 2 (x+3) + 5
= x^2 + 6x + 9 - 2x - 6 + 5
= x^2 + 4x +8

ket : ^ = pangkat

gof= g(fx)

= (x+3)² -2(x+3)+5
= x²+9 -2x-6 +5
= x² -2x +8