The point-slope form is a fundamental concept in algebra that allows us to describe the equation of a line when we know a point on the line and its slope. Understanding how to use this form can significantly enhance your graphing and analytical skills. In this article, we'll explore the point-slope form, work through a practice worksheet, and provide detailed explanations of the answers.
Understanding Point-Slope Form
The point-slope form of a line is written as:
[ y - y_1 = m(x - x_1) ]
Where:
- ( (x_1, y_1) ) is a point on the line,
- ( m ) is the slope of the line.
This equation is particularly useful when you have a slope and a point but do not necessarily have the y-intercept.
Why Use Point-Slope Form? π€
Using point-slope form can simplify the process of writing linear equations. Here are a few reasons to utilize this form:
- Ease of Use: Quickly plug in the point and the slope to find the lineβs equation.
- Visual Representation: Easily visualize how changing the slope or the point affects the line's graph.
- Real-World Applications: Useful in various fields such as economics, physics, and engineering, where relationships between variables can often be expressed as linear equations.
Practice Worksheet Breakdown π
Let's consider a practice worksheet where students are given several problems to solve involving the point-slope form. Below are sample problems along with their solutions and explanations.
Sample Problems
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Problem 1: Write the equation of a line with a slope of 3 that passes through the point (2, 4).
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Problem 2: Convert the point-slope equation ( y - 1 = -2(x - 3) ) to slope-intercept form.
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Problem 3: Determine the slope of a line that passes through the points (1, 2) and (4, 5).
Solutions
Problem 1 Solution
Using the point-slope form formula:
[ y - y_1 = m(x - x_1) ]
Substituting ( m = 3 ) and ( (x_1, y_1) = (2, 4) ):
[ y - 4 = 3(x - 2) ]
This is the equation of the line in point-slope form.
Problem 2 Solution
To convert the equation ( y - 1 = -2(x - 3) ) into slope-intercept form ( y = mx + b ):
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Distribute the (-2):
[ y - 1 = -2x + 6 ]
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Add (1) to both sides:
[ y = -2x + 7 ]
This shows the equation in slope-intercept form, where the slope is (-2) and the y-intercept is (7).
Problem 3 Solution
To find the slope between the points (1, 2) and (4, 5):
- The formula for the slope ( m ) between two points ((x_1, y_1)) and ((x_2, y_2)) is:
[ m = \frac{y_2 - y_1}{x_2 - x_1} ]
Substituting the given points:
[ m = \frac{5 - 2}{4 - 1} = \frac{3}{3} = 1 ]
The slope of the line is (1).
Summary of Solutions
Here is a summarized table of the problems and their solutions:
<table> <tr> <th>Problem</th> <th>Solution</th> </tr> <tr> <td>1. Write the equation with slope 3 through (2, 4)</td> <td>y - 4 = 3(x - 2)</td> </tr> <tr> <td>2. Convert y - 1 = -2(x - 3) to slope-intercept</td> <td>y = -2x + 7</td> </tr> <tr> <td>3. Find the slope between (1, 2) and (4, 5)</td> <td>m = 1</td> </tr> </table>
Important Notes π
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Slope Interpretation: The slope ( m ) indicates the steepness of the line. A positive slope rises from left to right, while a negative slope falls from left to right.
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Using the Right Form: Always make sure you are using the appropriate form depending on the information given. If you have two points, you may need to calculate the slope first before using point-slope form.
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Graphing: When graphing, start at the point ((x_1, y_1)), and then use the slope (m) to determine the next point on the line.
Practice Makes Perfect π
Practicing various types of problems using the point-slope form is crucial to mastering this concept. Create your own problems or use worksheets available online to enhance your skills further. The more you practice, the more comfortable you'll become with recognizing when and how to apply the point-slope form.
In conclusion, the point-slope form is a valuable tool for understanding linear relationships in algebra. Whether you're a student seeking help with homework or an educator looking to teach this concept effectively, these explanations and examples will be helpful. Keep practicing, and soon enough, the point-slope form will become second nature to you!