diketahui fungsi f(x)=x²-2x+3 dan fungsi g(x-2)=20-2x. fungsi komposisi (g°f)(x) adalah

f(x) = x^2 - 2x + 3
g(x-2) = 20 - 2x


misalkan :
t = x - 2 sehingga x = t + 2

g(x - 2) = 20 - 2x
g(t) = 20 - 2(t + 2)
g(t) = 20 - 2t - 4
g(t) = -2t + 16
g(x) = -2x + 16

(g○f)(x) = g(f(x))
(g○f)(x) = g(x^2 - 2x + 3)
(g○f)(x) = -2(x^2 - 2x + 3) + 16
(g○f)(x) = -2x^2 + 4x - 6 + 16
(g○f)(x) = -2x^2 + 4x + 10