Answer
$\lim\limits_{x \to -\infty}x^3 = \infty$
Work Step by Step
Let $f(x) =x^3$
This function is defined on the interval $(-\infty,\infty)$
Let $M \gt 1$ be given.
Let $N = M$
Suppose that $x \gt N$
Then:
$x^3 \gt x \gt N = M$
Therefore, $\lim\limits_{x \to \infty}x^3 = \infty$
