![Page 1: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/1.jpg)
Chapter 4 4-7 Point slope Form
![Page 2: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/2.jpg)
ObjectivesO Graph a line and write a linear
equation using point-slope form.
O Write a linear equation given two points.
![Page 3: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/3.jpg)
Slope formulaO If you know the slope and any point
on the line, you can write an equation of the line by using the slope formula. For example, suppose a line has a slope of 3 and contains (2, 1) . Let (x, y) be any other point on the line.
![Page 4: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/4.jpg)
Slope formula
![Page 5: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/5.jpg)
Point-slope formula
![Page 6: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/6.jpg)
Example#1O Write an equation in point slope
form for the line with the given slope that contains the given point.
![Page 7: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/7.jpg)
Example #2O Write an equation in point slope
form for the line with the given slope that contains the given point.
O slope = 1; (–1, –4)
![Page 8: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/8.jpg)
Example#3O Write an equation in point slope
form for the line with the given slope that contains the given point.
![Page 9: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/9.jpg)
Student guided practice
O Do problems 1-3 in your book page 279.
![Page 10: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/10.jpg)
Point-slope formO In previous lessons, you graphed a
line given its equation in slope-intercept form. You can also graph a line when given its equation in point-slope form. Start by using the equation to identify a point on the line. Then use the slope of the line to identify a second point.
![Page 11: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/11.jpg)
Example#4O Graph the line described by the
equation.O y – 1 = 2(x – 3)O Solution:O y – 1 = 2(x – 3) is in the form O y – y1= m(x – x1).
O The line contains the point (3, 1).
![Page 12: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/12.jpg)
SolutionExample#4
O Step 1 Plot (3, 1).O Step 2 Count 2 units up and 1 unit
right and plot another point.O Step 3 Draw the line connecting the
two points.
![Page 13: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/13.jpg)
Example#5O Graph the line described by the
equation.
![Page 14: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/14.jpg)
Solution to Example#5
O Step 1 Plot (–2, 4).O Step 2 Count 3 units up and 4 units
right and plot another point.O Step 3 Draw the line connecting the
two points.
![Page 15: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/15.jpg)
Example#6O Graph the line described by the
equation.O y + 3 = 0(x – 4)
![Page 16: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/16.jpg)
Solution to example#6O Step 1 Plot (4, –3).O Step 2 There slope is 0. Every value
of x will be at y = –3.O Step 3 Draw the line connecting the
points.
![Page 17: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/17.jpg)
Student guided practice
O Do problems 4-6 in your book page 279
![Page 18: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/18.jpg)
Exaxmple#7O Write the equation that
describes each line in slope-intercept form.
O Slope = 3, (–1, 4) is on the line.O Solution:O Step 1 Write the equation in point-
slope form:O y – y1 = m(x – x1)
O y – 4 = 3[x – (–1)]
![Page 19: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/19.jpg)
Solution to Example#7O Step 2 Write the equation in slope-
intercept form by solving for y.O y – 4 = 3(x + 1).O y – 4 = 3x + 3Distribute 3 on the right
side.+ 4 + 4 Add 4 to both sides.
y = 3x + 7
![Page 20: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/20.jpg)
Example#8O Write the equation that
describes the line in slope-intercept form.
O (2, –3) and (4, 1)
![Page 21: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/21.jpg)
Example#9O Write the equation that
describes the line in slope-intercept form.
![Page 22: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/22.jpg)
Student guided practice
O Do problems 7-9 in your book page 279
![Page 23: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/23.jpg)
Finding intercepts O The points (1, –2) and (3, 10) are
on a line . Find the intercepts.
![Page 24: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/24.jpg)
Example#10O The points (2, 15) and (–4, –3) are
on a line. Find the intercepts.
![Page 25: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/25.jpg)
Student guided practice
O Do problems 13 and 14 in your book page 279.
![Page 26: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/26.jpg)
Problem solving application
O The cost to stain a deck is a linear function of the deck’s area. The cost to stain 100, 250, 400 square feet are shown in the table. Write an equation in slope-intercept form that represents the function. Then find the cost to stain a deck whose area is 75 square feet.
![Page 27: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/27.jpg)
solution
![Page 28: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/28.jpg)
Problem solving application
O What if…? At a newspaper the costs to place an ad for one week are shown. Write an equation in slope-intercept form that represents this linear function. Then find the cost of an ad that is 21 lines long.
![Page 29: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/29.jpg)
solution
![Page 30: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/30.jpg)
Homework O Do evens problems from 23-33 pg.
280
![Page 31: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/31.jpg)
ClosureO Today we learned how to write
equations in slope intercept form.O Next class we are going to have a
discovery activity to find the line of best fit.
![Page 32: Chapter 4 4-7 Point slope Form. Objectives O Graph a line and write a linear equation using point-slope form. O Write a linear equation given two points](https://reader033.vdocuments.us/reader033/viewer/2022061512/56649db45503460f94aa5052/html5/thumbnails/32.jpg)
Have a great day