Obliczenia :
f(x) = 4x² - 8
f(2) = 4 * 2² - 8 = 4 * 4 - 8 = 16 - 8 = 8
f(12) = 4 * 12² - 8 = 4 * 144 - 8 = 576 - 8 = 568
