Page 36 - E-MODUL FUNGSI KOMPOSISI DAN FUNGSI INVERS

Latihan soal pembelajaran 2
No Jawaban Skor

1. a. Misalkan g (x) = y maka,

y = −6
2

2xy = x – 6

2xy – x = – 6

x (2y – 1) = – 6

x = −6
2 – 1 10

-1
g (x) = −6
2 – 1
Misalkan h (x) = y maka,
y = 2x – 7

y + 7 = 2x

+ 7 = x atau x = + 7
2 2
-1
h (x) = + 7
2
b. Cara 1

-1
-1
-1
(g o h) (x) = (h o g ) (x)
−6 + 7 −6+14 −7
= 2 – 1 = 2 – 1 = −6+14 −7 = −6+14 −7 =
2 2 2(2 −1) 4 −2

14 −13

4 −2
-1
-1
-1
(h o g) (x) = (g o h ) (x) 10
−6
−6
−6
−6
= + 7 = 2 +14 = 2 +14−2 = 2 +12 =
2 ( )− 1 − 1
2 2 2 2

−12 −6
=
2 +12 +6
Cara 2
(g o h) (x) = g (h(x))
= g (2x – 7)
= (2x – 7)−6
2(2x – 7)
= 2x −13
4x – 14

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