Diketahui (fog)(x) = 4x + 2x – 5. Tentukan:

Penjelasan dengan langkah-langkah:

a.) fog (x) = 4x + 2x – 5

fog (x) = 6x – 5

g(x) = 2x + 1

misal a = 2x + 1

a – 1 = 2x

a/2 – 1/2 = x

fog (x) = f(g(x))

6x – 5 = f(2x+1)

6x – 5 = f (2x+1)

6(a/2 – 1/2) – 5 = f(a)

6a/2 – 3 – 5 = f(a)

3a – 8 = f(a)

ganti a dengan x

3x – 8 = f(x)

f(x) = 3x – 8

b.) fog (x) = 4x + 2x – 5

fog (x) = 6x -5

f(x) = 2x + 1

fog (x) = f(g(x))

6x – 5 = 2(g(x)) + 1

6x – 5 – 1 = 2(g(x))

6x – 6 = 2(g(x))

6x/2 – 6/2 = g(x)

3x – 3 = g(x)