Chapter 11: Problem 24
Find parametric equations for the line with the given properties. Slope \(-2,\) passing through \((-10,-20)\)
Short Answer
Expert verified
x(t) = -10 + t and y(t) = -20 - 2t are the parametric equations of the line.
Step by step solution
01
Understand the line equation
The general parametric equations for lines involve a direction vector and a point through which the line passes. In 2-dimensional space, this involves finding expressions for both the x and y coordinates in terms of a parameter, usually denoted as \( t \).
02
Determine direction vector
The slope given is \(-2\). The direction for the line can be represented by the vector \((1, -2)\). This means for every unit increase in \(x\), \(y\) decreases by 2 because of the slope \(-2\).
03
Use point to form equations
We have the point \((-10, -20)\). Using this, we can form the equations as follows: **Equation for x:** Start with \(-10\) and add the change in \(x\), which is \(1 \times t\), so \(x = -10 + t\). **Equation for y:** Start with \(-20\) and add the change in \(y\), which follows the slope \(-2\), so \(y = -20 - 2t\).
04
Write final parametric equations
Using the point-slope concept from the previous steps, the parametric equations of the line are:\[\begin{align*}x(t) & = -10 + t \y(t) & = -20 - 2t\end{align*}\]
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.
Direction Vector
In the context of parametric equations, the direction vector is a key component that defines how a line progresses through a coordinate plane. Imagine a line as a path that starts at a given point and follows a specific direction indefinitely. This trajectory is captured by the direction vector.
A direction vector shows the relative changes in the x and y directions for each step along the line. In our example, the slope of y given is y y a 2, so we choose the vector The Direction Vector: (1, -2) An important thing to note:
A direction vector shows the relative changes in the x and y directions for each step along the line. In our example, the slope of y given is y y a 2, so we choose the vector The Direction Vector: (1, -2) An important thing to note:
- The direction vector (1, -2) tells us that as x increases by 1 unit, y decreases by 2 units.
- This vector is crucial because it maintains the given slope across the line.
Slope
The slope refers to the steepness or incline of a line on a coordinate plane. It is mathematically defined as the 'rise over run', which in simpler terms is the change in y over the change in x.
For any two points on a line, the slope can be calculated as:\[\text{Slope} (m) = \frac{\Delta y}{\Delta x}\]where \( \Delta y \) is the change in y-values and \( \Delta x \) is the change in x-values.
The Negative Slope: -2
For any two points on a line, the slope can be calculated as:\[\text{Slope} (m) = \frac{\Delta y}{\Delta x}\]where \( \Delta y \) is the change in y-values and \( \Delta x \) is the change in x-values.
The Negative Slope: -2
- Our line has a slope of 2. This indicates for every 1 unit the line moves horizontally, it moves 2 units down vertically.
- A negative slope means the line descends as it moves to the right, visualizing the idea of a hill going downhill.
Point-Slope Form
The concept of point-slope form is a powerful tool for writing equations of lines. It uses a known point and the slope to define the line's equation efficiently.
The formula for point-slope form is:\[(y - y_1) = m(x - x_1)\]where:
Applying Point-Slope FormIn this example:
The formula for point-slope form is:\[(y - y_1) = m(x - x_1)\]where:
- \(m\) is the slope
- \((x_1, y_1)\) are the coordinates of the known point.
Applying Point-Slope FormIn this example:
- We have a slope: 2
- We have a point: (-10, -20)
- Using the point-slope form helps us transition directly into creating parametric equations.
2-Dimensional Space
2-dimensional space (or 2D space) refers to a plane consisting of two axes: x and y. These axes form the basis for plotting points and visualizing geometric shapes, like lines, circles, and parabolas.
Understanding 2D Space
Understanding 2D Space
- The x-axis runs horizontally, while the y-axis runs vertically.
- Any point in this space is denoted as \((x, y)\), showing its position relative to both axes.
- In this problem, our line with slope 2 suggests a downward trend, with T representing progress along x and y.