Chapter 0: Problem 49
\(47-52\) : Express the inequality in interval notation, and then graph the
corresponding interval.
$$
-2
Short Answer
Expert verified
The interval is \((-2, 1]\).
Step by step solution
01
Analyze the Inequality
The given inequality is \(-2 < x \leq 1\). This indicates that \(x\) is greater than \(-2\) and less than or equal to \(1\).
02
Determine Interval Format
Based on the inequality \(-2 < x \leq 1\), use a parenthesis for \(-2\) since it is not included (\(<\) symbol) and a bracket for \(1\) since \(x\) can equal to \(1\) (\(\leq\) symbol).
03
Express in Interval Notation
The interval is \((-2, 1]\). This means all numbers between \(-2\) and \(1\), including \(1\) but not \(-2\), are part of the interval.
04
Graph the Interval
Draw a number line and represent the interval \((-2, 1]\) by marking an open circle at \(-2\) (to show \(-2\) is not included) and a closed dot at \(1\) (to show \(1\) is included). Then shade the region between them.
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.
Interval Notation
Interval notation is a way of representing the set of numbers that satisfy a particular range or inequality. It uses parentheses and brackets to show whether endpoints are included or excluded.
In interval notation,
Interval notation offers a concise way to convey ranges and can be helpful in understanding the scope of solutions to a problem.
In interval notation,
- Parentheses
( )are used when the number is not included. - Brackets
[ ]are used when the number is included.
Interval notation offers a concise way to convey ranges and can be helpful in understanding the scope of solutions to a problem.
Graphing Inequalities
Graphing inequalities helps visualize the range of values that satisfy the inequality. You represent inequalities on a number line as intervals.
The method involves the following steps:
For example, for the interval \((-2, 1]\), we place an open circle at \(-2\) and a closed circle at \(1\), then shade the number line in between to indicate all numbers \(x\) that satisfy the condition \(-2 < x \leq 1\).
This visual representation supports a clear understanding of the inequality's reach.
The method involves the following steps:
- Identify the inequality signs involved.
- Use open circles for strict inequalities (
<or>), meaning the endpoint is not included. - Use closed circles (or solid dots) for inclusive inequalities (
\leqor\geq), meaning the endpoint is included.
For example, for the interval \((-2, 1]\), we place an open circle at \(-2\) and a closed circle at \(1\), then shade the number line in between to indicate all numbers \(x\) that satisfy the condition \(-2 < x \leq 1\).
This visual representation supports a clear understanding of the inequality's reach.
Number Line Representation
A number line provides a simple, visual way to show the range of an inequality. It clearly marks the inclusion or exclusion of boundary values and the solution set.
Here's how to use a number line for the inequality \(-2 < x \leq 1\):
Here's how to use a number line for the inequality \(-2 < x \leq 1\):
- Draw a horizontal line to represent the number line.
- Plot key points \(-2\) and \(1\) on this line.
- Place an open circle at \(-2\) to show that \(-2\) is not part of the solution.
- Use a closed circle at \(1\) because \(1\) is included in the solution (inclusivity).
- Shade the portion of the line located between \(-2\) and \(1\) to demonstrate all values that \(x\) can take.