Question

Diketahui f(x) = x^2 - 4
(fof) (x) = 0
Ditanya : nilai x =...?

Answer 1

F(x) = x² - 4
fof(x) = 0 

f{f(x)} = 0
f{x²-4} = 0
(x²-4)² - 4 = 0
(x²-4)² = 4
x² -4 = 2 atau x² - 4 = -2
x² = 6 atau x² = 2
x = √6 atau x = - √6
x = √2 atau x = - √2

HP x = (-√6, - √2, 2 , 6)