Question

Diketahui (g o f) (x) = 4x^2 + 4x dan g(x) = x^2-1 tentukanlah nilai f(x-2)

Answer 1

(gof) (x) = 4x^2 + 4x
g (f(x)) = 4x^2 + 4x
x^2-1 (f(x)) = 4x^2 + 4x
xnya diganti ma f(x), maka
(f(x))^2 - 1 = 4x^2 + 4x
(f(x))^2 = 4x^2 + 4x +1
(f(x))^2 = (2x+1) (2x+1)
diakarin, maka
f(x) = 2x+1
pertanyaan: berapa f(x-2) = ...?
f(x-2) = 2(x-2) + 1
f(x-2) = 2x - 4 + 1
f(x-2) = 2x -3

semoga bermanfaat :)))