Chapter 1: Problem 35
Solve the inequalities in Exercises \(35-42 .\) Express the solution sets as intervals or unions of intervals and show them on the real line. Use the result \(\sqrt{a^{2}}=|a|\) as appropriate. $$ x^{2}<2 $$
Short Answer
Expert verified
The solution is \((-\sqrt{2}, \sqrt{2})\).
Step by step solution
01
Understand the Inequality
The inequality given is \( x^2 < 2 \). This means we are looking for all values of \( x \) whose square is less than 2.
02
Solve Using Square Roots
Take the square root on both sides of the inequality \( x^2 < 2 \). We obtain \( |x| < \sqrt{2} \). The result tells us that \( x \) must be within the range of \( -\sqrt{2} < x < \sqrt{2} \).
03
Express the Solution as an Interval
The solution to the inequality can be expressed as the interval \((-\sqrt{2}, \sqrt{2})\). This represents all real numbers \( x \) that are greater than \(-\sqrt{2}\) and less than \(\sqrt{2}\).
04
Visualize on the Real Line
To show the solution on the real line, draw a line with open circles at \(-\sqrt{2}\) and \(\sqrt{2}\). Shade the region between the circles, indicating that all numbers within this range satisfy the inequality.
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.
Square Roots
The square root of a number is a special value that, when multiplied by itself, gives the original number. For instance, the square root of 9 is 3, because 3 multiplied by itself equals 9. When solving inequalities like \( x^2 < 2 \), taking square roots helps determine the range of values that a variable can have.
In this context, it's important to understand:
In this context, it's important to understand:
- Square roots provide a way to move from squared values back to their original counterparts.
- The expression \( \sqrt{a^2} = |a| \) is crucial because it tells us that the square root of a squared value results in the absolute value of that original number.
- This property allows us to express solutions involving inequalities as intervals on the number line.
Absolute Value
Absolute value is a mathematical concept that measures the distance of a number from zero on the real number line. It is always positive or zero, never negative. For example, the absolute value of both -3 and 3 is 3. This concept is particularly useful in understanding solutions that involve inequalities and square roots.
- The absolute value of a number \( x \), written as \( |x| \), represents its magnitude without considering its direction (positive or negative).
- It plays a significant role when working with square roots, as seen in the inequality \( x^2 < 2 \).
- Through the transformation \( x^2 < 2 \) to \( |x| < \sqrt{2} \), we identify that \( x \) is restricted to being within a particular range on the real line.
Real Line
The real line is a representation of all real numbers in a continuous, infinite line. Each point on this line corresponds to a unique real number. It is used extensively to visualize solutions to inequalities and intervals especially when showing which values satisfy a condition.
- The numbers are arranged from left to right in increasing order, extending infinitely in both directions.
- When expressing solutions like \( -\sqrt{2} < x < \sqrt{2} \) visually, we can shade the section of the real line between the points \(-\sqrt{2}\) and \(\sqrt{2}\).
- Open or closed circles show whether endpoints are included or not. For instance, open circles at these points indicate that neither \(-\sqrt{2}\) nor \(\sqrt{2}\) are part of the solution.
Intervals
Intervals are a way of describing a set of numbers between two endpoints. They can be open, closed, or a combination, depending on whether the endpoints are included in the set. For the inequality \( x^2 < 2 \), the solution is expressed as an interval.
- An open interval, \((a, b)\), includes all numbers between \(a\) and \(b\) but not \(a\) and \(b\) themselves. Thus \(( -\sqrt{2}, \sqrt{2} )\) means all numbers more than \(-\sqrt{2}\) and less than \(\sqrt{2}\).
- Conversely, a closed interval \([a, b]\) includes the endpoints \(a\) and \(b\).
- Intervals offer concise notation for describing solutions and constraints in mathematics, and are essential in expressing the range of valid solutions for inequalities.