f(x) = 5x+1 dan g(x-1) = x² maka (fog) (2) =

Mapel : Matematika

Kelas : 10

Bab : Relasi dan Fungsi


→ f(x) = 5x + 1

→ g(x - 1) = x²


Ditanya :
→ (f o g) (x)


Jawaban :

→ Cari nilai g(x)

Misalkan :

x - 1 = y

x = y + 1

→ Nilai fungsi g(x)

g(x) = (x + 1)²

g(x) = x² + 2x + 1


→ Fungsi (f o g) (x)

(f o g) (x) = f(x² + 2x + 1)

(f o g) (x) = 5(x² + 2x + 1) + 1

(f o g) (x) = 5x² + 10x + 6


Maka, nilai (f o g) (2) :

= 5(2)² + 10(2) + 6

= 20 + 20 + 6

= 46 ✔