Wednesday, March 2, 2016

Single Variable Calculus, Chapter 2, 2.3, Section 2.3, Problem 5

Determine the $\lim\limits_{x \rightarrow 8} \quad (1+\sqrt[3]{x})(2-6x^2+x^3)$ and justify each step by indicating the appropriate limit law(s).



$
\begin{equation}
\begin{aligned}
\lim\limits_{x \rightarrow 8} \quad (1+\sqrt[3]{x})(2-6x^2+x^3) &= \lim\limits_{x \rightarrow 8} (1+x^{\frac{1}{3}}) \cdot
\lim\limits_{x \rightarrow 8} (2-6x^2+x^3)
&& \text{(Product Law)}\\
\lim\limits_{x \rightarrow 8} \quad (1+\sqrt[3]{x})(2-6x^2+x^3) &= \lim\limits_{x \rightarrow 8} \left(
\lim\limits_{x \rightarrow 8} 1 +
\lim\limits_{x \rightarrow 8} x^{\frac{1}{3}}
\right)
\left(
\lim\limits_{x \rightarrow 8} 2 -
6\lim\limits_{x \rightarrow 8} x^2 +
\lim\limits_{x \rightarrow 8} x^3
\right)
&& \text{(Sum, Difference and Constant Multiple Law)}\\
\lim\limits_{x \rightarrow 8} \quad (1+\sqrt[3]{x})(2-6x^2+x^3) &= \left[
1+(8)^{\frac{1}{3}}
\right]
\left[
2-6(8)^2+(8)^3
\right]
&& \text{(Constant, Power Special Limit Law)}
\end{aligned}
\end{equation}\\
\boxed{\lim\limits_{x \rightarrow 8} \quad (1+\sqrt[3]{x})(2-6x^2+x^3) = 390}
$

No comments:

Post a Comment

Why is the fact that the Americans are helping the Russians important?

In the late author Tom Clancy’s first novel, The Hunt for Red October, the assistance rendered to the Russians by the United States is impor...