Chapter 7: Problem 90
Determine whether each pair of lines is parallel, perpendicular, or neither $$ 2 x+y=6 \text { and } x-y=4 $$
Short Answer
Expert verified
Neither
Step by step solution
01
Convert Equations to Slope-Intercept Form
The slope-intercept form of a line is given by the equation: \( y = mx + b \) where \( m \) is the slope and \( b \) is the y-intercept. First, convert the first equation \( 2x + y = 6 \) to this form by solving for \( y \).
02
Solve the First Equation
Start by isolating \( y \): \( y = -2x + 6 \). This shows that the slope \( m_1 \) of the first line is -2.
03
Convert the Second Equation to Slope-Intercept Form
Next, convert the second equation \( x - y = 4 \) into slope-intercept form by solving for \( y \).
04
Solve the Second Equation
Isolate \( y \): \( y = x - 4 \). This shows that the slope \( m_2 \) of the second line is 1.
05
Compare the Slopes
Recall that: - Lines are parallel if and only if their slopes \( m \) are equal.- Lines are perpendicular if the product of their slopes is -1.- If neither condition is met, the lines are neither parallel nor perpendicular.Here, \( m_1 = -2 \) and \( m_2 = 1 \). Since \( -2 e 1 \) and \( -2 \times 1 = -2 eq -1 \), the lines are neither parallel nor perpendicular.
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.
Slope-Intercept Form
The slope-intercept form is a simple and common way to write the equation of a line. It is written as: \[ y = mx + b \]
- \( y \) is the dependent variable or the value of the function at any point.
- \( m \) is the slope of the line. It indicates how steep the line is and its direction—positive for upward, negative for downward.
- \( x \) is the independent variable.
- \( b \) is the y-intercept, which is the point where the line crosses the y-axis.
Solving Linear Equations
Solving linear equations often requires manipulating the equation to isolate the variable of interest. Let's look at the second equation from our problem: \( x - y = 4 \). To convert this into slope-intercept form, we need to solve for \( y \). Start by subtracting \( x \) from both sides: \[ -y = -x + 4 \]. Next, multiply every term by -1 to solve for \( y \): \[ y = x - 4 \].
- The slope \( m \) here is 1.
- The y-intercept \( b \) is -4.
Slope Comparison
Comparing slopes is essential to determine if lines are parallel, perpendicular, or neither. Here are the basics:
1. \( m_1 = -2 \) and \( m_2 = 1 \) are not equal, so the lines are not parallel.
2. The product of their slopes is \( -2 \times 1 = -2 \), which is not equal to -1. Thus, they are not perpendicular.
Therefore, the lines represented by the equations \( 2x + y = 6 \) and \( x - y = 4 \) are neither parallel nor perpendicular. Understanding slope comparison helps in solving similar problems and validating the relationships between different lines.
- Lines are parallel if their slopes \( m \) are the same.
- Lines are perpendicular if the product of their slopes is -1.
- If neither condition is met, the lines are neither parallel nor perpendicular.
1. \( m_1 = -2 \) and \( m_2 = 1 \) are not equal, so the lines are not parallel.
2. The product of their slopes is \( -2 \times 1 = -2 \), which is not equal to -1. Thus, they are not perpendicular.
Therefore, the lines represented by the equations \( 2x + y = 6 \) and \( x - y = 4 \) are neither parallel nor perpendicular. Understanding slope comparison helps in solving similar problems and validating the relationships between different lines.