f(x) = x³ - 3x² + 4

f'(x) = 3x² - 6x

f'(x) = 0

3x² - 6x = 0

3x(x - 2) = 0

x = 0 или x = 2

-∞__+__( 0 )_-_( 2 )__+__+∞

f'(x) > 0 при x ∈ (-∞; 0) и x ∈ (2; +∞)

f'(x) < 0 при x ∈ (0; 2)