Chapter 10: Problem 3
\(x^{2}+10 x+2=0\)
Short Answer
Expert verified
The solutions are \(x = -5 + \sqrt{23}\) and \(x = -5 - \sqrt{23}\).
Step by step solution
01
Identify the Equation Type
The given equation is a quadratic equation of the form \(ax^2 + bx + c = 0\). Here, \(a = 1\), \(b = 10\), and \(c = 2\).
02
Apply the Quadratic Formula
The quadratic formula is \(x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\). We will use this formula to find the solutions to the equation.
03
Substitute Values into the Quadratic Formula
Substitute \(a = 1\), \(b = 10\), and \(c = 2\) into the quadratic formula:\[ x = \frac{-10 \pm \sqrt{10^2 - 4 \cdot 1 \cdot 2}}{2 \cdot 1} \]This simplifies to:\[ x = \frac{-10 \pm \sqrt{100 - 8}}{2} \]\[ x = \frac{-10 \pm \sqrt{92}}{2} \]
04
Simplify the Expression
Simplify \(\sqrt{92}\):\(\sqrt{92} = \sqrt{4 \times 23} = 2\sqrt{23}\).Substitute back into the equation:\[ x = \frac{-10 \pm 2\sqrt{23}}{2} \]
05
Solve for x
Divide both terms in the numerator by 2:\[ x = \frac{-10}{2} \pm \frac{2\sqrt{23}}{2} \]This gives:\[ x = -5 \pm \sqrt{23} \]Thus, the solutions are \(x = -5 + \sqrt{23}\) and \(x = -5 - \sqrt{23}\).
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Quadratic Formula
The quadratic formula is a powerful tool for solving quadratic equations. Quadratic equations are polynomial equations of the form \( ax^2 + bx + c = 0 \), where \( a \), \( b \), and \( c \) are constants. The standard form ensures every term is aligned properly, with the highest degree term (\( x^2 \)) first.
The quadratic formula itself is expressed as:
When the discriminant is positive, the equation has two distinct real solutions. If it's zero, there is exactly one real solution. On the other hand, a negative discriminant means no real solutions, but you can find complex ones. In our context, we substitute the specific values of \( a \), \( b \), and \( c \) to find the exact solutions for our quadratic equation.
The quadratic formula itself is expressed as:
- \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \)
When the discriminant is positive, the equation has two distinct real solutions. If it's zero, there is exactly one real solution. On the other hand, a negative discriminant means no real solutions, but you can find complex ones. In our context, we substitute the specific values of \( a \), \( b \), and \( c \) to find the exact solutions for our quadratic equation.
Solving Equations
To solve quadratic equations, we use the quadratic formula. The first step is to plug in the values of \( a \), \( b \), and \( c \) from the equation into the formula. For the given equation, \( x^2 + 10x + 2 = 0 \), we identified that \( a = 1 \), \( b = 10 \), and \( c = 2 \).
Substituting these into the formula gives us:
Substituting these into the formula gives us:
- \( x = \frac{-10 \pm \sqrt{10^2 - 4 \cdot 1 \cdot 2}}{2 \cdot 1} \)
- \( x = \frac{-10 \pm \sqrt{92}}{2} \)
Simplifying Radicals
Simplifying radicals is a task often encountered when using the quadratic formula. When we reach
a stage where we are required to take the square root of a number, simplifying the radical simplifies the work. In our problem, to simplify \( \sqrt{92} \), we identify its prime factors.
The number 92 factors into 2 and 23, specifically \( 92 = 4 \times 23 \). Since 4 is a perfect square, we can simplify \( \sqrt{92} \) as \( \sqrt{4 \times 23} = 2\sqrt{23} \).
This reduced radical reflects a more straightforward form of the expression and grows our understanding of number properties.
Simplifying radicals yields an easier expression to work with when continuing to solve for \( x \). In practice, this means replacing \( \sqrt{92} \) with \( 2\sqrt{23} \), and subsequently substituting back into our equation, we can then solve for \( x \) easily:
a stage where we are required to take the square root of a number, simplifying the radical simplifies the work. In our problem, to simplify \( \sqrt{92} \), we identify its prime factors.
The number 92 factors into 2 and 23, specifically \( 92 = 4 \times 23 \). Since 4 is a perfect square, we can simplify \( \sqrt{92} \) as \( \sqrt{4 \times 23} = 2\sqrt{23} \).
This reduced radical reflects a more straightforward form of the expression and grows our understanding of number properties.
Simplifying radicals yields an easier expression to work with when continuing to solve for \( x \). In practice, this means replacing \( \sqrt{92} \) with \( 2\sqrt{23} \), and subsequently substituting back into our equation, we can then solve for \( x \) easily:
- \( x = \frac{-10 \pm 2\sqrt{23}}{2} \)