Writing Equations in Point-Slope Form
_The Point-Slope form of a linear equation will tell you just what the name says, a point on the line and the slope.
_ m= slope and (x1, y1) are a point on the line
Visit this website and look at the difference between slope-intercept and point-slope forms of linear equations: http://regentsprep.org/Regents/math/ALGEBRA/AC1/EqLines.htm. Notice the examples of horizontal and vertical lines.
Here is a great way to remember the formula:
Visit this website and look at the difference between slope-intercept and point-slope forms of linear equations: http://regentsprep.org/Regents/math/ALGEBRA/AC1/EqLines.htm. Notice the examples of horizontal and vertical lines.
Here is a great way to remember the formula:
___If the video above is not working, you need to download the Adobe Flash player.
If you know a point and the slope, it is easy to substitute them into the formula.
Write the equation of a line that contains the point (-2, 1) and has a slope of 5.
Substituting in the values, we get: y - (1) = 5(x - (-2))
Simplify: y - 1 = 5(x + 2)
Sometimes you are given two points and no slope. We can use our formula for slope to find the slope and then pick one of the points to use to write the equation.
A line contains the points (-1, 6 ) and (-2, -2). Write an equation for the line in point-slope form; then write an equation in y-intercept form.
Find the slope of the line: m = - 2 - 6 = -8 = -8 = 8
-2 - (-1) -2 + 1 -1
Plug in the values for slope and one of the points:
y - 6 = 8(x - (- 1))
Simplify to: y - 6 = 8(x + 1)
Here's another way to find slope and write an equation in Point-Slope form and then convert it into Slope-Intercept form:
If you know a point and the slope, it is easy to substitute them into the formula.
Write the equation of a line that contains the point (-2, 1) and has a slope of 5.
Substituting in the values, we get: y - (1) = 5(x - (-2))
Simplify: y - 1 = 5(x + 2)
Sometimes you are given two points and no slope. We can use our formula for slope to find the slope and then pick one of the points to use to write the equation.
A line contains the points (-1, 6 ) and (-2, -2). Write an equation for the line in point-slope form; then write an equation in y-intercept form.
Find the slope of the line: m = - 2 - 6 = -8 = -8 = 8
-2 - (-1) -2 + 1 -1
Plug in the values for slope and one of the points:
y - 6 = 8(x - (- 1))
Simplify to: y - 6 = 8(x + 1)
Here's another way to find slope and write an equation in Point-Slope form and then convert it into Slope-Intercept form:
PRACTICE
The slide show below gives more examples of writing equations in Point-Slope Form. It also has some word problems worked out. Try doing the problems on your own and checking your answers.
Chapter 5 Point Slope Form
View more presentations from Iinternational Program School
http://www.slideshare.net/mrzeidan/chapter-5-point-slope-form
ASSESS
Do this interactive quiz: http://www.thatquiz.org/tq/practicetest?5zl78my1nts
Let's move on to writing equations in Standard Form.
ASSESS
Do this interactive quiz: http://www.thatquiz.org/tq/practicetest?5zl78my1nts
Let's move on to writing equations in Standard Form.