Chapter 1: Problem 54
The given equation involves a power of the variable. Find all real solutions of the equation. \(x^{2}-7=0\)
Short Answer
Expert verified
The real solutions are \(x = \sqrt{7}\) and \(x = -\sqrt{7}\).
Step by step solution
01
Identify the Equation
The given equation is a quadratic equation, and it is written as: \(x^{2}-7=0\). Our goal is to find all real solutions for \(x\).
02
Isolate the Quadratic Term
To solve for \(x\), first isolate the \(x^2\) term by adding 7 to both sides of the equation: \(x^{2} = 7\).
03
Solve for x
To find the values of \(x\), take the square root of both sides. This gives us two possible solutions: \(x = \pm\sqrt{7}\).
04
Confirm the Solutions
Verify the solutions by substituting them back into the original equation. For \(x = \sqrt{7}\): \((\sqrt{7})^2 = 7\). For \(x = -\sqrt{7}\): \((-\sqrt{7})^2 = 7\). Both satisfy the original equation.
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Solving Quadratics
Quadratic equations are expressions that follow the pattern: \( ax^2 + bx + c = 0 \). In these equations, \( a \), \( b \), and \( c \) are constants, with the variable \( x \) being raised to the second power or squared. Solving a quadratic equation involves finding the value of \( x \) that makes the equation true, known as the roots or solutions of the equation.
To solve, we often follow these steps:
To solve, we often follow these steps:
- Identify the quadratic equation and ensure all terms are on one side.
- Isolate the quadratic term by performing algebraic operations.
- Use methods like factoring, completing the square, or the quadratic formula to solve for \( x \).
Square Roots
Taking square roots is a fundamental concept in solving quadratic equations, especially ones like \( x^2 = n \). When you "take the square root" of both sides of an equation, you're essentially finding a value that, when multiplied by itself, gives the desired number.
For example, if you have \( x^2 = 7 \), the square root of 7 will provide the solutions, \( x = \pm \sqrt{7} \).
For example, if you have \( x^2 = 7 \), the square root of 7 will provide the solutions, \( x = \pm \sqrt{7} \).
- The symbol \( \pm \) is important here. It indicates there are two possible solutions: one positive and one negative. This is because both \( (\sqrt{7})^2 \) and \( (-\sqrt{7})^2 \) equal 7.
- Remember that the square root process introduces these two potential answers because a square is always non-negative, so both positive and negative roots are considered.
Real Solutions
In the context of quadratic equations, real solutions refer to the values of \( x \) that are real numbers. Not all quadratic equations have real solutions; sometimes the roots are complex. However, when solving equations like \( x^2 = 7 \), the solutions are real because \( \sqrt{7} \) is a real number.
- Real numbers include all the numbers on the number line: positive numbers, negative numbers, zero, and fractions or irrational numbers like \( \sqrt{7} \).
- In our specific equation \( x^2 - 7 = 0 \), we obtain real solutions because we're dealing with positive quantities (squaring a number and setting it equal to a positive value).