Page 54 - E-MODUL Fungsi komposisi dan fungsi invers

– 1
b. g (10) = 10+38
12
48
– 1
g (10) =
12
5
– 1
g (10) = 4
3. f(x) = 5x + 6, g(x) = x - 2 dan h(x) = 3

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

= f (g (3x)

= f (3x - 2)

= 5(3x - 2) + 6

= 15x – 10 + 6

= 15x – 4

Misalkan (f o g o h) (x) = y , maka

y = 15x – 4 20

y + 4 = 15x

+4 +4
= x atau x =
15 15
-1
(f o g o h) (x) = +4
15
-1
Berapa nilai x jika (f o g o h) (x) = 5 ?
-1
(f o g o h) (x) = +4 = 5
15

+4 = 5
15
x + 4 = 75

x = 75 – 4

x = 71

Modul Elektronik Menggunakan Pendekatan Kontekstual | 46