Question

Bila f(x) memenuhi 2f(x) + f(1-x) = x^2 utk semua nilai real x maka f(x)?

Answer 1

Misal:
x = 1 - x maka
2f(x) + f(1 - x) = x²       --> kali 2
2f(1 - x) + f(x) = (1 - x)² --> kali 1
___________________________ _
3f(x) = 2x² - (x² - 2x + 1)
3f(x) = x² + 2x - 1
f(x) = (1/3)x² + (2/3)x - 1/3