## Calculus (3rd Edition)

(a) $\lim _{x \rightarrow \infty} x^3=\infty$. (b) $\lim _{x \rightarrow -\infty} x^3=-\infty$. (c) $\lim _{x \rightarrow -\infty} x^4=\infty$.
(a) Since $3\gt 0$, then we have $\lim _{x \rightarrow \infty} x^3=\infty$. (b) Since $3\gt 0$ and odd, then we have $\lim _{x \rightarrow -\infty} x^3=-\infty$. (c) Since $4\gt 0$ and even, then we have $\lim _{x \rightarrow -\infty} x^4=\infty$.