Tentukan f(x) jika diketahui g(x) = x+5 dan (f0g)(x) = x2+5x-6

jawab
fungsi

g(x) = x + 5
fog(x) = x² + 5x - 6
f (x+ 5) = x² + 5x - 6
f(x) = (x-5)² + 5(x - 5) - 6
f(x) = x² -10x + 25+ 5x - 25 - 6
f(x) = x² - 5x  - 6

[Fungsi Komposisi dan Fungsi Invers]

Fog(x) = x² + 5x - 6
f(g(x)) = x² + 5x - 6
f(x + 5) = x² + 5x - 6
f(x + 5) = x² + 10x + 25 - 5x - 25 - 6
f(x + 5) = (x + 5)² - 5(x + 5) - 6
f(x) = x² - 5x - 6