The function is such that . Consider two statements :
Statement 1 : there exists x₁, x₂ (2, 4), x₁ < x₂, such that f'(x₁) = 1 and f'(x₂) = 0.
Statement 2 : there exists x₃, x₄ (2, 4), x₃ < x₄, such that f is decreasing in (2, x₄), increasing in (x₄, 4) and .
Then