Kunci Jawaban Try Out Matematika 1 Buku Sukino IPA no 18

Try Out Ujian Nasional Matematika IPA Paket 1
Matematika Sukino Peminatan Kelas XII
Soal Ujian Nasional Matematika IPA
Try Out Matematika IPA
Soal dan Pembahasan Buku Matematika Sukino

18. Diketahui f(x) = (2 - 3x)/(4x + 1) ; x≠1/4. Jika f^-1(x)adalah invers fungsi f, maka f^-1(x - 2) = ...

a. (4 - x)/(4x -5);  x≠5/4
b. (-x - 4)/(4x - 5); x≠5/4
c. (-x + 2)/(4x + 3); x≠-3/4
d. x/(4x + 3); x≠-3/4
e. -x/(4x + 5); x≠-5/4

Jawaban : A

f(x) = (2 - 3x)/(4x + 1)
y (4x + 1) = 2 - 3x
4xy + y = 2 - 3x
4xy + 3x = 2 - y
x (4y + 3) = 2 - y
x = (2 - y) / (4y + 3)

f^-1(x) = (2 - x) / (4x + 3)

f^-1(x - 2) =  (2 - (x - 2)) / ( 4 (x - 2) + 3)
f^-1(x - 2) = (-x + 4) / (4x - 8 + 3)
f^-1(x - 2) = (4 - x) / (4x - 5)

>>soal no 19