Chapter 4: Problem 58
Solve the rational inequality (a) symbolically and (b) graphically. $$ \frac{1}{x^{2}}>0 $$
Short Answer
Expert verified
The inequality holds for all real numbers except \(x = 0\).
Step by step solution
01
Understand the Inequality
The given inequality is \(\frac{1}{x^{2}} > 0\). The goal is to determine for which values of \(x\) the expression \(\frac{1}{x^{2}}\) is greater than zero.
02
Analyze the Denominator
The denominator \(x^2\) is the square of \(x\). A square of any real number (other than zero) is always positive. Therefore, \(x^2 > 0\) for all \(x eq 0\).
03
Solve the Inequality Symbolically
Since \(\frac{1}{x^{2}}\) has its domain where \(x^2 eq 0\), it must be \(x eq 0\). Given that \(x^2 > 0\) for all \(x eq 0\), the inequality \(\frac{1}{x^{2}} > 0\) holds true for all \(x eq 0\).
04
Graphically Solve the Inequality
Plot the function \(y = \frac{1}{x^2}\). Notice that the graph approaches the x-axis but never touches or crosses it, indicating that \(\frac{1}{x^2}\) remains positive for all defined values of \(x\) except at \(x = 0\), where it is undefined.
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.
Symbolic Solving
In order to solve a rational inequality symbolically, you need to break down the inequality into understandable parts. Take, for instance, the inequality \( \frac{1}{x^2} > 0 \). Here, your task is to find out which values of \( x \) satisfy the condition that \( \frac{1}{x^2} \) is greater than zero.
### Steps for Symbolic Solving:
### Steps for Symbolic Solving:
- **Analyze the inequality:** Begin by understanding the structure of the inequality. Notice that dividing by \( x^2 \) is the same as multiplying by \( \frac{1}{x^2} \).
- **Examine the denominator:** The term \( x^2 \) represents a squared number. This is significant because any number squared, except zero, is always positive. This means \( x^2 > 0 \) for all \( x eq 0 \).
- **Solve the inequality:** Since the denominator \( x^2 \) is never zero (except when \( x \) is zero), the entire expression \( \frac{1}{x^2} \) is positive for all \( x eq 0 \). Hence, \( \frac{1}{x^2} > 0 \) is true everywhere except \( x = 0 \), where it is undefined.
Graphical Representation
Graphical representation gives a visual understanding of rational inequalities. Let's consider the function \( y = \frac{1}{x^2} \) and how it behaves when plotted.
### Visualizing Graphically:
### Visualizing Graphically:
- **Graph the function:** Start by sketching the graph of \( y = \frac{1}{x^2} \). Notice that as \( x \) moves away from zero either positively or negatively, the function goes upwards, forming a U-shaped curve.
- **Observe the graph at zero:** The function is undefined at \( x = 0 \) because you cannot divide by zero. But as \( x \) gets closer to zero, the values of \( y \) get extremely large.
- **Analyze the x-axis:** The graph never touches the x-axis. This indicates that \( \frac{1}{x^2} \) never becomes zero or negative; it remains positive for all other values of \( x \).
Denominator Analysis
Analyzing the denominator in rational inequalities is crucial since it directly influences whether an expression is defined and whether it can change sign.
### Understanding Denominator Analysis:
### Understanding Denominator Analysis:
- **Importance of the denominator:** In a fraction like \( \frac{1}{x^2} \), the denominator \( x^2 \) is enforced by its attributes. Because \( x^2 \) is a squared number, it's inherently non-negative (\( x^2 \geq 0 \)).
- **Behavior of squared expressions:** For any real number other than zero, \( x^2 \) remains strictly positive. This means that within the domain where \( x eq 0 \), \( x^2 \) ensures the entire fraction stays positive.
- **Key takeaway:** Analyzing the denominator helps conclude that the expression remains undefined when \( x = 0 \) and positive elsewhere. It's a fundamental part of determining where the inequality holds true across real numbers.