Diketahui f(x) = x - 2, h(x) = x2 + 2x –2, x > 0 dan (fogoh)(x)= x2 + 6 maka g(6) = … (A) 12 (B) 14 (C) 20 (D) -4 (E) tak hingga

Fungsi Komposisi

x² + 2x - 2 = 6
x² + 2x - 8 = 0
(x + 4)(x - 2) = 0
x = -4 (ditolak) atau x = 2

(f o g o h)(2) = 2² + 6
(f o {g(h(2))} = 10
f(g(6)) = 10
= g(6) - 2 = 10
= g(6) = 12 [A]