Question

Tentukan (f °g)(x) dan (g°f)(x) dari fungsi berikut ini.

a.f(x)= 2-4x dan g(x) = 2x*3 + 2

Answer 1

F(x) = 2 - 4x
g(x) = 2x³ + 2

f ° g (x) = f ( g (x) )
= 2 - 4 (2x³ + 2)
= 2 - 8x³ - 8

g ° f (x) = g ( f (x) )
= 2 (2 - 4x)³ + 2
= 2 (4 - 16x + 16x²) (2 - 4x) + 2
= 2 (8 - 16x - 32x + 64x² + 32x² - 64x³) + 2
= 2 (8 - 48x + 96x² - 64x³) + 2
= 18 - 96x + 192x² - 128x³