Chapter 10: Problem 16
Find the coordinates of the foot of the perpendicular from the point \((2,-6)\) to the line \(3 y-x+2=0\).
Short Answer
Expert verified
(1/5, -3/5)
Step by step solution
01
- Understand the problem
Identify the given point \( (2, -6) \) and the line equation \( 3y - x + 2 = 0 \). The task is to find the coordinates of the foot of the perpendicular from the given point to the line.
02
- Find the slope of the given line
Rewrite the line equation in slope-intercept form \( y = mx + c \). Starting from \( 3y - x + 2 = 0 \), solve for \( y \): \[ 3y = x - 2 \] \[ y = \frac{1}{3} x - \frac{2}{3} \] This gives the slope of the line as \( m = \frac{1}{3} \).
03
- Determine the slope of the perpendicular line
The slope of the perpendicular line is the negative reciprocal of the original slope. Therefore, the slope of the perpendicular line is \(-3 \).
04
- Write the equation of the perpendicular line
Using the point-slope form \((y - y_1 = m(x - x_1))\) and the slope from Step 3, the equation of the line passing through \( (2, -6) \) with a slope of \(-3\) is: \[ y + 6 = -3(x - 2) \] Simplify this to get: \[ y = -3x + 6 - 6 \] \[ y = -3x + 0 \] \[ y = -3x \]
05
- Solve for the intersection point
Set the y-values of the two equations equal to each other to find the intersection point (foot of the perpendicular). \[ \frac{1}{3}x - \frac{2}{3} = -3x \] Multiply through by 3 to clear the fraction: \[ x - 2 = -9x \] Solve for \( x \): \[ x + 9x = 2 \] \[ 10x = 2 \] \[ x = \frac{2}{10} \] \[ x = \frac{1}{5} \]
06
- Find the corresponding y-coordinate
Substitute \( x = \frac{1}{5} \) back into the original line equation to find the corresponding \( y \) coordinate. \[ y = \frac{1}{3} \left( \frac{1}{5} \right) - \frac{2}{3} \] \[ y = \frac{1}{15} - \frac{2}{3} = \frac{1}{15} - \frac{10}{15} \] \[ y = \frac{1 - 10}{15} = \frac{-9}{15} \] \[ y = -\frac{3}{5} \]
07
- State the coordinates of the foot of the perpendicular
The coordinates of the foot of the perpendicular from the point \( (2, -6) \) to the line \( 3y - x + 2 = 0 \) are \( \left( \frac{1}{5}, -\frac{3}{5} \right) \).
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.
line equation
To find the foot of the perpendicular from a point to a line, it is crucial to understand the line's equation. A line equation represents all the points along the line and can be written in various forms. In this task, we start with the equation in standard form: \[ 3y - x + 2 = 0 \]
To make it easier to work with, especially for finding slopes, we convert the standard form to the slope-intercept form \( y = mx + c \). This form shows the slope \( m \) and the y-intercept \( c \). Here's how we transform the given line equation:
Starting with \( 3y - x + 2 = 0 \), we solve for \( y \):
\[ 3y = x - 2 \]\[ y = \frac{1}{3} x - \frac{2}{3} \]
Now we see that the slope \( m \) is \( \frac{1}{3} \) and the y-intercept \( c \) is \( -\frac{2}{3} \).
To make it easier to work with, especially for finding slopes, we convert the standard form to the slope-intercept form \( y = mx + c \). This form shows the slope \( m \) and the y-intercept \( c \). Here's how we transform the given line equation:
Starting with \( 3y - x + 2 = 0 \), we solve for \( y \):
\[ 3y = x - 2 \]\[ y = \frac{1}{3} x - \frac{2}{3} \]
Now we see that the slope \( m \) is \( \frac{1}{3} \) and the y-intercept \( c \) is \( -\frac{2}{3} \).
slope
Understanding slope is essential to solving geometry problems involving lines. The slope \( m \) measures the steepness and direction of a line. In the slope-intercept form \( y = mx + c \), \( m \) is the coefficient of \( x \). A positive slope means the line rises as it moves from left to right, while a negative slope means it falls.
To find the slope of a perpendicular line, we use the negative reciprocal of the original slope. For the given line, with slope \( \frac{1}{3} \), the perpendicular slope is \( -3 \).
We use this new slope along with the coordinates of the given point \( (2, -6) \) to form the equation of the perpendicular line using the point-slope form: \( y - y_1 = m(x - x_1) \).
Thus, the perpendicular line equation is:
\[ y + 6 = -3(x - 2) \]
Simplifying, we get \( y = -3x \).
To find the slope of a perpendicular line, we use the negative reciprocal of the original slope. For the given line, with slope \( \frac{1}{3} \), the perpendicular slope is \( -3 \).
We use this new slope along with the coordinates of the given point \( (2, -6) \) to form the equation of the perpendicular line using the point-slope form: \( y - y_1 = m(x - x_1) \).
Thus, the perpendicular line equation is:
\[ y + 6 = -3(x - 2) \]
Simplifying, we get \( y = -3x \).
coordinates
Coordinates indicate the position of points in a plane. They are typically in the format \( (x, y) \). To find where two lines intersect, we set their equations equal to each other and solve for \( x \) and \( y \).
Here, we had:\[ \frac{1}{3}x - \frac{2}{3} = -3x \]
Multiplying through by 3 to remove the fractions, we get:\[ x - 2 = -9x \]Solving for \( x \) gives:\[ 10x = 2 \]\[ x = \frac{1}{5} \]Substituting \( x = \frac{1}{5} \) back into the original line equation \( y = \frac{1}{3}x - \frac{2}{3} \), we find \( y \):\[ y = \frac{1}{15} - \frac{10}{15} \]\[ y = -\frac{3}{5} \]Thus, the coordinates of the foot of the perpendicular from \( (2, -6) \) to the line \( 3y - x + 2 = 0 \) are \( \left( \frac{1}{5}, -\frac{3}{5} \right) \).
Here, we had:\[ \frac{1}{3}x - \frac{2}{3} = -3x \]
Multiplying through by 3 to remove the fractions, we get:\[ x - 2 = -9x \]Solving for \( x \) gives:\[ 10x = 2 \]\[ x = \frac{1}{5} \]Substituting \( x = \frac{1}{5} \) back into the original line equation \( y = \frac{1}{3}x - \frac{2}{3} \), we find \( y \):\[ y = \frac{1}{15} - \frac{10}{15} \]\[ y = -\frac{3}{5} \]Thus, the coordinates of the foot of the perpendicular from \( (2, -6) \) to the line \( 3y - x + 2 = 0 \) are \( \left( \frac{1}{5}, -\frac{3}{5} \right) \).