Chapter 1: Problem 23
\(23-48\) Solve the inequality. Express the answer using interval notation. $$ |X| \leq 4 $$
Short Answer
Expert verified
The solution is \([-4, 4]\).
Step by step solution
01
Understanding Absolute Value Inequality
The inequality \(|x| \leq 4\) represents the set of numbers whose distance from zero is less than or equal to 4. This can be represented as two simple inequalities: 1. \(x \leq 4\)2. \(x \geq -4\).
02
Solve the Inequalities Separately
We solve each of the inequalities separately: For \(x \leq 4\), the solution is all real numbers less than or equal to 4.For \(x \geq -4\), the solution is all real numbers greater than or equal to -4.
03
Combine the Solutions
The solution to \(|x| \leq 4\) is the intersection of the solutions to the two inequalities: \(-4 \leq x \leq 4\). This means that \(x\) lies between -4 and 4, inclusive of the boundaries.
04
Express in Interval Notation
The interval notation for the solution \(-4 \leq x \leq 4\) is:\([-4, 4]\). This means that the solution includes all numbers from -4 to 4, including -4 and 4 themselves.
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 an efficient way to describe a range of numbers, especially when dealing with inequalities. When we talk about interval notation, we are essentially describing a set of numbers between two bounds. In the case of the inequality \(-4 \leq x \leq 4\), the interval notation is written as \([-4, 4]\).
- The square brackets \([\text{ } ]\) indicate that the endpoints -4 and 4 are included in the set. This is because the inequality is "less than or equal to," which means that x can be equal to the boundary numbers.
- If the endpoints weren’t included (if, for example, it was \(-4 \lt x \lt 4\)), we would use round brackets \((\text{ )}\) instead.
Inequality Solutions
To solve inequality problems, especially those involving absolute values, we need to first understand the equality represented. For the inequality \(|x| \leq 4\), we're interested in all values of \(x\) whose absolute value does not exceed 4. Think of it as finding the numbers at most 4 units away from zero on a number line.
- We break down the inequality \(|x| \leq 4\) into two separate linear inequalities: \(x \leq 4\) and \(x \geq -4\).
- By solving these inequalities individually, we find the allowable values for \(x\). These solutions are then combined to form a complete set of numbers that satisfy the original inequality.
Algebraic Expressions
Algebraic expressions are mathematical phrases that contain numbers, variables, and operations. In the inequality \(|x| \leq 4\), \(x\) is our variable, and the expression is designed to represent a constraint on the values that \(x\) can take.
- Absolute value expressions like \(|x|\) deal with distance; they show how far the number is from zero, regardless of direction. This makes these expressions particularly useful in defining conditions with spatial implications.
- Algebraic manipulation often involves simplifying or rearranging expressions to isolate the variable of interest, as seen when breaking down \(|x| \leq 4\) into \(x \leq 4\) and \(x \geq -4\).