Chapter 10: Problem 81
Solve each equation. Approximate the solutions to the nearest hundredth when appropriate. $$ m^{2}-7 m+3=0 $$
Short Answer
Expert verified
Solutions are approximately \( m \approx 6.54 \) and \( m \approx 0.46 \).
Step by step solution
01
Identify the Type of Equation
The given equation is a quadratic equation in the form of \( ax^2 + bx + c = 0 \). In this problem, \( a = 1 \), \( b = -7 \), and \( c = 3 \).
02
Use the Quadratic Formula
The solutions for a quadratic equation \( ax^2 + bx + c = 0 \) are given by the quadratic formula: \[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \]. Substitute \( a = 1 \), \( b = -7 \), and \( c = 3 \) into the formula.
03
Calculate the Discriminant
The discriminant of the quadratic formula is \( b^2 - 4ac \). Compute the discriminant: \( (-7)^2 - 4 \times 1 \times 3 = 49 - 12 = 37 \). Since the discriminant is positive, there are two distinct real roots.
04
Substitute and Simplify
Substitute the values into the quadratic formula: \[ m = \frac{-(-7) \pm \sqrt{37}}{2 \times 1} \]. Simplify to \[ m = \frac{7 \pm \sqrt{37}}{2} \].
05
Approximate Solutions
Calculate the approximate value of \( \sqrt{37} \) which is approximately \( 6.08276 \). Then, solve for both values: 1. \( m_1 = \frac{7 + 6.08276}{2} \approx 6.54 \)2. \( m_2 = \frac{7 - 6.08276}{2} \approx 0.46 \).
06
Verify the Approximations
Verify the approximations by substituting the values back into the original equation to check for correctness: - For \( m_1 \): \( (6.54)^2 - 7 \times 6.54 + 3 \approx 42.7716 - 45.78 + 3 = 0.0084 \approximately 0 \).- For \( m_2 \): \( (0.46)^2 - 7 \times 0.46 + 3 \approx 0.2116 - 3.22 + 3 = -0.0084 \approximately 0 \). Both approximations are correct.
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.
Quadratic Formula
The quadratic formula is a handy tool for solving quadratic equations, which are equations in the form of \( ax^2 + bx + c = 0 \). This formula provides the roots, or solutions, for any quadratic equation:
To solve the example equation \( m^2 - 7m + 3 = 0 \), we identify \( a = 1 \), \( b = -7 \), and \( c = 3 \). Substituting these values into the quadratic formula will help us find the roots of this equation.
- \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \)
To solve the example equation \( m^2 - 7m + 3 = 0 \), we identify \( a = 1 \), \( b = -7 \), and \( c = 3 \). Substituting these values into the quadratic formula will help us find the roots of this equation.
Discriminant
The discriminant is a key part of the quadratic formula, found under the square root symbol: \( b^2 - 4ac \). This part of the formula is crucial because it tells us the nature of the roots:
- If the discriminant is positive, there are two distinct real roots.
- If the discriminant is zero, there is exactly one real root, often referred to as a repeated root.
- If the discriminant is negative, there are no real roots - instead, the roots are complex numbers.
Real Roots
Real roots are solutions to the quadratic equation that are real numbers, meaning they can be plotted on a number line. After determining from the discriminant that our equation has two real roots, we substitute the values into the quadratic formula to solve for them.
- In the current problem, we resolve to find \( m = \frac{7 \pm \sqrt{37}}{2} \).
- Calculating \( \sqrt{37} \) gives approximately \( 6.08276 \).
- \( m_1 = \frac{7 + 6.08276}{2} \approx 6.54 \)
- \( m_2 = \frac{7 - 6.08276}{2} \approx 0.46 \)