Answer
(a) $\pi$
(b) $\pi$
Work Step by Step
In this exercise we use the result $\lim\limits_{x \to _-^+\infty}(\frac{1}{x^\frac{m}{n}})$=$0$ when ever $\frac{m}{n}$$\gt$$0$.
This result follows immediately from Theorem 8 and the power rule in Theorem $1$:
$\lim\limits_{x \to _-^+\infty}$ $(\frac{1}{x^\frac{m}{n}})$=$\lim\limits_{x \to _-^+\infty}(\frac{1}{x})^\frac{m}{n}$=$(\lim\limits_{x \to
_-^+\infty}\frac{1}{x})^\frac{m}{n}$=$0^\frac{m}{n}$=$0$
(a) $\pi$
(b) $\pi$