Page 40 - MODUL KELAS X FUNGSI KOMPOSISI DAN FUNGSI INVERS

3xy – 2x = 4y - 2

x (3y – 2)= 4y - 2

4 − 2
x =
3 −2
-1
f (y) = 4 − 2
3 −2

-1
f (k) = 4 − 2
3 −2
4 − 2
2 =
3 −2
2 (3k – 2) = 4k - 2

6k – 4 = 4k – 2

6k – 4k = -2 + 4

2k = 2

2
k = k = 1
2
Contoh 3:

3
Ditentukan f(x) = 2x – 3, g(x) = x + 2 dan h(x) = , x ≠ 0. Carilah nilai

–1
x sehingga (ℎ ) ( ) = 1!
Penyelesaian:

( )( ) = (2x – 3) + 2 = 2x - 1

3
(ℎ ( ))( ) =
2 −1
Misalkan (ℎ ( ))( ) = y, maka:
3
y =
2 −1
2xy - y = 3

2xy = 3 + y
3+
x =
2

-1
(ℎ ( )) ( ) = 3+
2

Modul Elektronik Menggunakan Pendekatan Kontekstual | 34