Chapter 4: Problem 42
Find an equation of the line containing the two given points. Express your answer in the indicated form. \((2,1)\) and \((4,6) ;\) standard form
Short Answer
Expert verified
The equation of the line containing the two given points, (2,1) and (4,6), in standard form is \(5x - 2y = 8\).
Step by step solution
01
Find the Slope
To find the slope of the line, we will use the slope formula: \(m = \frac{y_2 - y_1}{x_2 - x_1}\), where \((x_1, y_1)\) and \((x_2, y_2)\) are the coordinates of the two given points. Plugging in the values of the points \((2,1)\) and \((4,6)\), we get:
\(m = \frac{6 - 1}{4 - 2} = \frac{5}{2}\)
So, the slope of the line is \(\frac{5}{2}\).
02
Use Point-Slope Form
With the slope calculated in Step 1, we can now use the point-slope form to find the equation of the line. The point-slope form is given by:
\(y - y_1 = m(x - x_1)\), where \((x_1, y_1)\) is one of the given points and \(m\) is the slope.
Using the point \((2,1)\) and the slope \(\frac{5}{2}\), we have:
\(y - 1 = \frac{5}{2}(x - 2)\)
03
Convert to Standard Form
To convert the equation to standard form, we need to eliminate the fractions and have the terms arranged in the form \(Ax + By = C\).
Start by multiplying both sides of the equation by \(2\) to eliminate the fraction:
\(2(y - 1) = 5(x - 2)\)
Distribute the numbers on both sides:
\(2y - 2 = 5x - 10\)
Now, move the terms with variables to the left side of the equation and the constant terms to the right side:
\(-5x + 2y = -8\)
The equation is now in standard form, though it's preferable to have the leading coefficient positive. Multiply the equation by \(-1\) to make coefficient of \(x\) positive:
\(5x - 2y = 8\)
The equation of the line containing the two given points in standard form is \(\boxed{5x - 2y = 8}\).
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 Formula
Finding the slope of a line is crucial in understanding its inclination or steepness between two points. The slope formula is expressed as \( m = \frac{y_2 - y_1}{x_2 - x_1} \). This simple mathematical expression allows us to measure the vertical change (rise) over the horizontal change (run) between two coordinates.
- For the points \((2, 1)\) and \((4, 6)\), substitute these into the formula to find the slope \(m\).
- The coordinates show us that \(x_1 = 2\), \(y_1 = 1\), \(x_2 = 4\), and \(y_2 = 6\). By substituting, we get \( m = \frac{6 - 1}{4 - 2} = \frac{5}{2} \).
- This calculation tells us that for every 2 units moved horizontally, the line moves 5 units vertically upward.
Point-Slope Form
Once we have the slope, we can use it along with any point on the line to express the equation of the line in point-slope form. The point-slope form is given by \( y - y_1 = m(x - x_1) \). It is especially useful when a point and a slope are known.
- Picking the point \((2, 1)\) and slope \( \frac{5}{2} \), the equation becomes \( y - 1 = \frac{5}{2}(x - 2) \).
- This form makes it easy to visualize how the line starts at a specific point and extends based on its slope.
- The resulting equation describes how the value of \(y\) changes with \(x\), moving from the known point \((x_1, y_1)\).
Standard Form
Standard form expresses the equation of a line as \( Ax + By = C \), where \(A\), \(B\), and \(C\) are integers, and \(A\) is typically non-negative. Using it helps make comparisons easier with other lines or fitting into coordinate systems.
- Start by multiplying both sides of the point-slope equation \( y - 1 = \frac{5}{2}(x - 2) \) by 2 to eliminate the fraction: \( 2(y - 1) = 5(x - 2) \).
- Distribute to get \( 2y - 2 = 5x - 10 \).
- Rearrange it into standard form \( -5x + 2y = -8 \) which simplifies to \( 5x - 2y = 8 \) by multiplying through by \(-1\).
Coordinate Geometry
Coordinate geometry, often known as analytic geometry, is the study of geometry using a coordinate system. It pairs algebra and geometry through graphs and coordinates, providing a clear graphical representation of equations. This field of mathematics is crucial for understanding the spatial relationships between different forms.
- The coordinate plane consists of two axes (x-axis and y-axis) that divide the plane into four quadrants.
- Points, lines, and curves are plotted, transforming abstract equations into visual graphs.
- The slope of a line elucidates the angle it forms with the axes, indicating inclination and direction.