1. Dik : (f•g)(x) = x^-6x+7 f(x) = x+3 dit : g(x)...? 2. Dik : (f•g)(x) = 3x-5/x+2 (x tidaksama dgn -2) g(x) = 2x-4 Dit : f(x)...? 3. Dik : (f•g)(x) = 4x^+8

1. Dik : (f•g)(x) = x^-6x+7
f(x) = x+3
dit : g(x)...?
Jawab :
f(g(x)) = x² - 6x + 7
g(x) + 3 = x² - 6x + 7
g(x) = x² - 6x + 4 ✔

2. Dik : (f•g)(x) = 3x-5/x+2 (x tidaksama dgn -2)
g(x) = 2x-4
Dit : f(x)...?
Jawab :
a = 2x - 4 ---> x = (a + 4)/2 = 2 + (a/2)

f(g(x)) = (3x - 5)/(x + 2)
f(a) = (3(2 + a/2) - 5) / (2 + a/2 + 2)
f(a) = (1 + a/2)/(4 + a/2)
f(x) = (2 + x)/(8 + x) ✔

3. Dik : (f•g)(x) = 4x^+8x-3
g(x) = 2x+4
Dit : f(-2)...?
Jawab :
f(-2) = f(g(x))
g(x) = -2
2x + 4 = -2
x = 3

f(-2) = f(g(x)) = 4.3² + 8.3 - 3
f(-2) = 57 ✔

4. Dik : g(x) = 2x+6
(f•g)(x) = 4x^+22x+18
Dit : f(x)...?
Jawab :
f(g(x)) = 4x² + 22x + 18
f(2x + 6) = (2x + 6)² - (2x + 6) - 12
f(x) = x² - x - 12 ✔

5. Fungsi f= R➡R dan fungsi g= R➡R
Dik : f(x) = x-7
(f•g)(x) = x^+12x+35
Dit : g(x)...?
Jawab :
f(g(x)) = x² + 12x + 35
g(x) - 7 = x² + 12x + 35
g(x) = x² + 12x + 42 ✔