va roooooooooooooooooog

E(x) = -4x² + 12x - 4 = -(4x² - 12x + 4) = -(4x² - 12x + 9 - 5) = -[(2x - 3)² - 5] = -(2x - 3)² + 5, ∀x ∈ R.
(2x - 3)² ≥ 0, ∀x ∈ R ==> -(2x - 3)² ≤ 0, ∀x ∈ R ==> -(2x - 3)² + 5 ≤ 5, ∀x ∈ R ==> E(x) ≤ 5, ∀x ∈ R ==> max(E(x)) = 5.
Răspuns: C.