Answer
$x \rightarrow\infty$
$P(x)\rightarrow -\infty$
$x\rightarrow\ - \infty$
$P(x)\rightarrow \infty$
Work Step by Step
$P(x) = -\frac{1}{8}x^{3}+\frac{1}{4}x^{2}+12x$
$Q(x)=-\frac{1}{8}x^{3}$
$x \rightarrow\infty$
$-\frac{1}{8} x^{3} \rightarrow-\frac{1}{8}(\infty)(\infty)(\infty) = - \infty$
$P(x)\rightarrow -\infty$
$x\rightarrow\ - \infty$
$-\frac{1}{8}x^ {3}\rightarrow-\frac{1}{8}(-\infty)(-\infty)(-\infty) = \infty$
$P(x)\rightarrow \infty$