Diketahui f (x) = 2x² - 3 dan g (x) = 3x + 7. tentukan fog dan gofnya???

Hi SusiNurmin

dik:
f(x)=2x^{2}-3
g(x)=3x+7
dit:(gof)(x) dan (fog)(x)?

jawab:

(fog)(x)=3(2x^{2}-3)+7
            =6x^{2}-9+7
            =6x^{2}-2

(gof)(x)=2(3x+7)^{2}-3
            =2(9x^{2}+42x+49)-3
            =18x^{2}+84x+98-3
            =18x^[2}+84x+95

salam
dejan04

Materi : Fungsi Komposisi

f(x) = 2x² - 3
g(x) = 3x + 7

maka
(fog)(x)
= f(g(x))
= f(3x + 7)
= 2(3x + 7)² - 3
= 2(9x² + 42x + 49) - 3
= 18x² + 84x + 95

(gof)(x)
= g(f(x))
= g(2x² - 3)
= 3(2x² - 3) + 7
= 6x² - 9 + 7
= 6x² - 2