a. f(x) = x² – 4 dan (f g)(x) = x² – 6x + 5
b. f(x) = x² + 8 dan (fog)(x) = 4×2 – 4x + 9
Tentukan g(x) jika:
Jawaban:
a.fog(x) = x² – 6x + 5
g(x) = √x² – 6x + 9
b.g(x) = x² + x – 4
(fog)(x) = 4x² + 4x – 9
(fog)(x) = 4x² + 4x – 9
f(g(x)) = 4x² + 4x – 9
f(x² + x – 4) = 4x² + 4x – 9
f(x² + x – 4) = 4(x² + x – 4) + 7
f(x) = 4x + 7
maka
f(x – 2) = 4x + 7
f(x – 2) = 4(x – 2) + 7
f(x – 2) = 4x – 8 + 7
f(x – 2) = 4x – 1