Answer
(a)$\frac{3}{4} $
(b)$\frac{3}{4} $
Work Step by Step
(a)\begin{align*}
\lim _{x \rightarrow \infty} \frac{3-(2 / x)}{4+\left(\sqrt{2} / x^{2}\right)}&=\frac{3-\lim _{x \rightarrow \infty}(2 / x)}{4+\lim _{x \rightarrow \infty}\left(\sqrt{2} / x^{2}\right)}\\
&=\frac{3-0}{4+0}\\
&= \frac{3}{4}
\end{align*}
(b)\begin{align*}
\lim _{x \rightarrow-\infty} \frac{3-(2 / x)}{4+\left(\sqrt{2} / x^{2}\right.}&=\frac{3-\lim _{x \rightarrow-\infty}(2 / x)}{4+\lim _{x \rightarrow-\infty}\left(\sqrt{2} / x^{2}\right)}\\
&=\frac{3-0}{4+0}\\
&=\frac{3}{4}
\end{align*}