Tentukanlah nilai maksimum f(x) = x3 - 12X +3

f(x) = x^3 - 12x + 3
f'(x) = 3x^2 - 12 = 0
=> 3(x^2 - 4) = 0
=> 3(x + 2)(x - 2) = 0
=> x = -2 atau x = 2
+++ (-2) --- (2) +++
Karena maksimum maka x = -2 (+++ ---)
Nilai balik maksimumnya
f(-2) = (-2)^3 - 12(-2) + 3 = -8 + 24 + 3 = 19