Page 21 - Bahan Ajar Matematika Dasar

14
Contoh

Diketahui f(x) = 2x + 5 dan g(x) = x –

−1
4. Tentukan( ) ?

Penyelesaian :

(f o g )(x) = f(g(x))

= f(x – 4)

= 2(x – 4) + 5

= 2x – 8 + 5

= 2x – 3

( ) −1 (x)

(f o g )(x) = 2x – 3

y = 2x – 3

2x – 3 = y

2x = y + 3

X = +3
2

−1
( ) (x) = +3
2