/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 55 Find the limits in Exercises \(5... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Find the limits in Exercises \(53-58.\) $$\lim \left(\frac{x^{2}}{2}-\frac{1}{x}\right)$$ \begin{equation} \begin{array}{ll}{\text { a. }} & {x \rightarrow 0^{+}} & {\text { b. } x \rightarrow 0^{-}} \\ {\text { c. }} & {x \rightarrow \sqrt[3]{2}} & {\text { d. } x \rightarrow-1}\end{array} \end{equation}

Short Answer

Expert verified
a. \( -\infty \); b. \( \infty \); c. finite; d. \( \frac{3}{2} \).

Step by step solution

01

Understanding the Expression

The expression given is \( \frac{x^2}{2} - \frac{1}{x} \). Our goal is to evaluate this limit under various conditions for \( x \): as \( x \to 0^+ \), \( x \to 0^- \), \( x \to \sqrt[3]{2} \), and \( x \to -1 \).
02

Find the Limit as \( x\to0^+ \)

As \( x \to 0^+ \), the term \( \frac{1}{x} \to +\infty \). Hence, the expression \( \frac{x^2}{2} - \frac{1}{x} \to -\infty \), since \( \frac{1}{x} \) dominates and is negative.
03

Find the Limit as \( x\to0^- \)

As \( x \to 0^- \), the term \( \frac{1}{x} \to -\infty \). Again, \( \frac{x^2}{2} - \frac{1}{x} \to +\infty \) because \( \frac{1}{x} \) dominates and is positive.
04

Find the Limit as \( x\to\sqrt[3]{2} \)

Substitute \( x = \sqrt[3]{2} \) directly into the expression since the function is continuous at this point: \[ \frac{(\sqrt[3]{2})^2}{2} - \frac{1}{\sqrt[3]{2}} = \frac{2^{2/3}}{2} - 2^{-1/3}. \] Simplify this using properties of exponents.
05

Simplified Expression for \( x\to\sqrt[3]{2} \)

Calculate \( 2^{2/3} \) and \( 2^{-1/3} \). The expression simplifies to: \[ \frac{2^{2/3}}{2} - 2^{-1/3} = \frac{\sqrt[3]{4}}{2} - \frac{1}{\sqrt[3]{2}}. \] Thus, the limit is a finite number.
06

Find the Limit as \( x\to-1 \)

Substitute \( x = -1 \) directly into the expression since it is continuous at \( x = -1 \): \[ \frac{(-1)^2}{2} - \frac{1}{-1} = \frac{1}{2} + 1 = \frac{3}{2}. \]
07

Conclusion: Consolidate Limits

The limits computed for each condition are: \( \lim_{x \to 0^+} -\infty \), \( \lim_{x \to 0^-} +\infty \), \( \lim_{x \to \sqrt[3]{2}} = \frac{2^{2/3}}{2} - 2^{-1/3} \), and \( \lim_{x \to -1} = \frac{3}{2} \).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Continuous Functions
Continuous functions are fundamental in calculus, representing functions without gaps, jumps, or abrupt changes within a specific interval. A function is continuous at a point if you can draw it without lifting your pencil from the paper in its graphical form. Mathematically, a function \( f(x) \) is continuous at a point \( x = a \) if the limit as \( x \) approaches \( a \) equals the function value at \( a \), i.e., \( \lim_{x \to a} f(x) = f(a) \).

Recognizing a continuous function allows students to substitute variables directly into the function when finding limits. In the given exercise, we dealt with continuous functions at points like \( x = \sqrt[3]{2} \) and \( x = -1 \). By direct substitution, we find the limit without the need for approximation or additional steps. This property simplifies our work significantly.
Continuous functions assure that minor changes in the input do not cause drastic swings in the function's output, supporting deeper analyses such as finding limits, derivatives, and integrals.
Limits at Infinity
In calculus, limits at infinity deal with the behavior of a function as the independent variable approaches infinity or negative infinity. This concept helps in understanding how functions behave when the values of \( x \) grow very large or very small, giving insights into the end behavior of the function.

For the expression in the exercise, particularly when analyzing \( x \to 0^+ \) and \( x \to 0^- \), we encounter infinite limits. The term \( \frac{1}{x} \) plays a crucial role as it tends to \( +\infty \) or \( -\infty \), depending on whether \( x \) approaches zero from the positive or negative side, respectively. This tells us about the vertical asymptotic behavior of the function near zero.
  • As \( x \to 0^+ \): \( \frac{1}{x} \to +\infty \), so the expression diverges to \( -\infty \).
  • As \( x \to 0^- \): \( \frac{1}{x} \to -\infty \), causing the expression to diverge to \( +\infty \).
Limits at infinity are invaluable for visualizing the growth, decay, and asymptotic tendencies of functions.
Properties of Exponents
The properties of exponents are a cornerstone for solving complex algebraic and calculus problems. These properties help simplify expressions and are crucial for evaluating limits and other mathematical operations. The basic exponent rules include:
  • \( a^{m} \times a^{n} = a^{m+n} \)
  • \( (a^{m})^{n} = a^{m \times n} \)
  • \( a^{0} = 1 \) for any \( a eq 0 \)
  • \( a^{-n} = \frac{1}{a^{n}} \)
In the given exercise, exponent properties are particularly useful when substituting \( x = \sqrt[3]{2} \). The expression involves simplifying terms like \( 2^{2/3} \) and \( 2^{-1/3} \), which use the negative exponent rule to express roots as fractions. This simplification provides a clear path to solving for the limit by transforming complex fractional exponents into more manageable numbers.

Understanding these exponent rules allows us to transform and evaluate expressions efficiently, revealing the true behavior of the function under the limit.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

At what points are the functions in Exercises 13-30 continuous? $$y=(2 x-1)^{1 / 3}$$

A fixed point theorem Suppose that a function \(f\) is continuous on the closed interval \([0,1]\) and that \(0 \leq f(x) \leq 1\) for every \(x\) in \([0,1] .\) Show that there must exist a number \(c\) in \([0,1]\) such that \(f(c)=c(c\) is called a fixed point of \(f)\)

Explain why the following five statements ask for the same information. \( \begin{array}{l}{\text { a. Find the roots of } f(x)=x^{3}-3 x-1} \\ {\text { b. Find the } x \text { -coordinates of the points where the curve y= }x^{3}} \\\ {\text { crosses the line } y=3 x+1 .} \\ {\text { c. Find all the values of } x \text { for which } x^{3}-3 x=1 \text { . }} \\ {\text { d. Find the } x \text { -coordinates of the points where the cubic curve }} \\ {\quad y=x^{3}-3 x \text { crosses the line } y=1 .} \\ {\text { e. Solve the equation } x^{3}-3 x-1=0}\end{array} \)

Use the Intermediate Value Theorem in Exercises \(69-76\) to prove that each equation has a solution. Then use a graphing calculator or computer grapher to solve the equations. $$ x(x-1)^{2}=1 \quad \text { (one root } ) $$

In Exercises \(47-50,\) graph the function \(f\) to see whether it appears to have a continuous extension to the origin. If it does, use Trace and Zoom to find a good candidate for the extended function's value at \(x=0\) .If the function does not appear to have a continuous extension, can it be extended to be continuous at the origin from the right or from the left? If so, what do you think the extended function's value(s) should be? $$ f(x)=\frac{10^{|x|}-1}{x} $$

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.