Ejemplo

Lim             (3x + 1)2 (x – 1)x
x → +∞       x3 – (x + 3)3

Lim             9x4 – 3x3 – 5x2 – x
x → +∞       x3 – (x3 + 9x2 + 27x + 27)

Lim            9x4 – 3x3 – 5x2 – x = -∞
x → +∞     –9x2 – 27x – 27