Question

1. Jika fungsi f : R → R, dan g : R → R jika g(x) = 2x - 4 dan (fog)(x) = 4x²
- 24x + 32, fungsi f(-2) adalah?
a. 12
b. 24
c. 32
d. 50
e. 96

2. Diberikan f(x) = 3x + 2 dan (gof)(x) = 9x² + 6x + 8, nilai f(-2)?
a. 128
b. 84
c. 22
d. 16
e. 10

Answer 1

Verified answer

Kelas 10 Matematika
Bab Fungsi Komposisi

1] 2x - 4 = -2
2x = 4 - 2
x = 2/2
x = 1

4x² - 24x + 32 
= 4 . 1² - 24 . 1 + 32
= 4 - 24 + 32
= 12

2] 3x + 2 = -2
3x = - 2 - 2
x = -4/3

9x² + 6x + 8
= 9 . (-4/3)² + 6 . (-4/3) + 8
= 9 . 16/9 - 8 + 8
= 16