Chapter 1: Problem 63
Find an equation of the line that satisfies the given conditions. \(x\) -intercept \(4 ; y\) -intercept -3
Short Answer
Expert verified
The equation of the line is \( y = \frac{3}{4}x - 3 \).
Step by step solution
01
Recognize Intercepts
An intercept is where a graph crosses the axis. The x-intercept is where the graph crosses the x-axis, and here it's given as 4, which means the point (4, 0) is on the line. The y-intercept is where the graph crosses the y-axis, and here it is given as -3, meaning the point (0, -3) is on the line.
02
Find Slope of the Line
Use the formula for slope, which is \( m = \frac{y_2 - y_1}{x_2 - x_1} \). Substitute the intercept points \((4, 0)\) and \((0, -3)\) into the formula:\[ m = \frac{0 - (-3)}{4 - 0} = \frac{3}{4} \]. Thus, the slope of the line is \( \frac{3}{4} \).
03
Write Equation in Point-Slope Form
Using the slope \( m = \frac{3}{4} \) and one of the points, let's use \((0, -3)\), apply the point-slope formula to write the equation: \( y - y_1 = m(x - x_1) \). Plugging in the values gives: \[ y - (-3) = \frac{3}{4}(x - 0) \]. Simplifying, \[ y + 3 = \frac{3}{4}x \].
04
Convert to Slope-Intercept Form
To put the equation into slope-intercept form \( y = mx + b \), solve for \( y \):\[ y = \frac{3}{4}x - 3 \]. This shows that the equation of the line is \( y = \frac{3}{4}x - 3 \), with slope \( \frac{3}{4} \) and y-intercept \(-3\).
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.
x-intercept
The "x-intercept" of a line in a coordinate plane is the point where the line crosses the x-axis. In mathematical terms, this is where the y value is zero. For example, if a line crosses the x-axis at the point (4, 0), the x-intercept is 4.
Identifying the x-intercept is crucial because it provides one of the coordinates needed to determine the line's equation.
Identifying the x-intercept is crucial because it provides one of the coordinates needed to determine the line's equation.
- It helps in calculating the slope of the line when you have another point on the line.
- Each x-intercept will have its own significance based on the context of a problem.
y-intercept
The "y-intercept" is where the line crosses the y-axis. This point always has an x-coordinate of 0. If the line crosses the y-axis at (0, -3), then the y-intercept is -3. This concept is just as important as the x-intercept, providing the necessary information to formulate a line's equation.
Here are some key points to remember:
Here are some key points to remember:
- The y-intercept is often represented by the constant "b" in the slope-intercept form of a line.
- It represents the point on the graph where the line starts on the y-axis.
slope-intercept form
The "slope-intercept form" of a linear equation is expressed as: \[ y = mx + b \]where "m" is the slope, and "b" is the y-intercept. This form is incredibly useful for quickly identifying the slope of the line and where it crosses the y-axis.
Understanding slope-intercept form allows for:
Understanding slope-intercept form allows for:
- Easy graphing with the slope and y-intercept guiding the direction and position of the line.
- Efficient translation of real-life situations into mathematical expressions.
point-slope form
The "point-slope form" is another way to express the equation of a line. It is especially useful when you know one point on the line and the slope. The formula is presented as: \[ y - y_1 = m(x - x_1) \]where (x_1, y_1) is the known point and "m" is the slope.
Some benefits of using the point-slope form include:
Some benefits of using the point-slope form include:
- Flexibility in identifying an equation when different points are known.
- Easy derivation to arrive at the slope-intercept form.