Odpowiedź :
x(x - 4) < 8
x² - 4x < 8
x² - 4x - 8 < 0
x² - 4x - 8 = 0
Δ = (-4)² - 4 * 1 * (-8) = 16 +32 = 48
√Δ = 4√3
x1 = 4 + 4√3 / 2 = 2 + 2√3
x2 = 2 - 2√3
x(x-4) < 8 dla x ∈ (2 - 2√3; 2 + 2√3)
x² - 4x < 8
x² - 4x - 8 < 0
x² - 4x - 8 = 0
Δ = (-4)² - 4 * 1 * (-8) = 16 +32 = 48
√Δ = 4√3
x1 = 4 + 4√3 / 2 = 2 + 2√3
x2 = 2 - 2√3
x(x-4) < 8 dla x ∈ (2 - 2√3; 2 + 2√3)