Jika h(x) = (2x3 – 4x2)(3x + 6), maka h’(-1) adalah …

u = 2x³ - 4x²           u' = 6x² - 8x
v = 3x + 6              v' = 3
h'(x) = u' v + v' u
        = (6x² - 8x) (3x + 6) + 3 (2x³ - 4x²)
        = 18x³ + 36x² - 24x² - 48x + (6x³ - 12x²)
        = 24x³ - 48x

(2x^3 - 4x^2)(3x + 6) = 6x^4 + 12x^3 - 12x^3 + 24x^2
= 6x^4 + 24x^2
misal f(x) = y
y = 6x^4 + 24x^2
6x^4 = 24x^2 - y
x = (24x^2 - y) / 6^4
= (24x^2 - y) / 1296
jadi f^-1 (x) = (24x^2 - x) / 1296