Jika (fog) (x) = 8× + 15 da g(×) = × +3 maka f ( ×- 2) =

(fog)(x) = 8x+15
g(x) = x+3
f(x-2) =....???


Penyelesaian

misal:
y = x+3
Inversnya: x = y-3

Maka
f(y) = 8(y-3) + 15
f(y) = 8y - 24 + 15
f(y) = 8y -9

Jd, f(x) = 8x-9

Maka:
f(x-2) = 8(x-2)-9
. = 8x - 16 - 9
. = 8x - 25

Bab Fungsi Komposisi
Matematika SMA Kelas X

(fog) (x) = 8x + 15
f(x + 3) = 8x + 15
f(x - 3 + 3) = 8 (x - 3) + 15
f(x) = 8x - 24 + 15
f(x - 2) = 8 (x - 2) - 9
f(x - 2) = 8x - 25