1. 5.4 Point-Slope Form of a Linear Equation
Standard: SWBAT derive linear equations by using the point-slope formula and be able to explain the sequence of steps.
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superposition of our Moon and the planets Venus and Jupiter

2. Mini Quiz 43
1. Find the x- and y-intercept of 3x – 4y = Graph the line y = Write the equation in Standard Form:

3. Quick Review
1. What is the Slope-Intercept Form? y = mx + b 2. What is the Standard Form? Ax + By = C 3. How does an equation of a vertical line look? What is the slope? x = #, slope = undefined 4. How does an equation of a horizontal line look? What is the slope? y = #, slope = 0

4. Overview Point-Slope Form Graphing Using Point-Slope Form
Writing an Equation in Point-Slope Form
Writing an Equation Using a Table
Forms we’ve learned so far…
Slope-Intercept Form: y = mx + b
Standard Form: Ax + By = C

5. Point-Slope Form y – y1 = m(x – x1)
Derived (came from) the slope formula:
(x1, y1) = (-2, -2)
(x, y)

6. Point-Slope Form We know the point (-2, -2), so x1 = -2 and y1 = -2
1. Write the equation in Point-Slope Form of the graph below:
(x1, y1) = (-2, -2)
We know the point (-2, -2), so x1 = -2 and y1 = -2
(x, y)
We know the slope is 2/3
Plug it into the Point-Slope Form:

7. Graphing Using Point-Slope Form
2. Graph the equation
What is the ordered pair?
(x1, y1) =
What is the slope?
m =
(2, 5)
(2, 5)

8. Graphing Using Point-Slope Form
3. Graph the equation
What is the ordered pair?
(x1, y1) =
What is the slope?
m =
(-2, 5)

9. Write an Equation in Point-Slope Form Given a Point and a Slope
y + 3 = 4(x + 1)
5. (-10, 0); Slope = 2
y = 2(x +10)
6. (-4, 3); Slope = -6
y – 3 = -6(x +4)

10. Write an Equation in Point-Slope Form Given Two Points
Steps:
Find the slope between the two points.
Pick one point to use in order to write the equation.
Plug in the slope and coordinate from the point into the Point-Slope Form

11. Write an Equation in Point-Slope Form Given Two Points
7. (-3, 6) and (1, -2)
y – 6 = -2(x + 3) or y + 2 = -2(x – 1)
8. (-2, 3) and (-1, 1)
y – 3 = -2(x + 2) or y – 1 = -2(x + 1)
9. (-2, -5) and (7, -6)
y + 5 = (x + 2) or y + 6 = - (x – 7)

12. Writing an Equation from a Table
What is the independent and dependent variable?
x – independent; y – dependent
Find the rate of change:
What is the slope?
4/10 = 2/5
What is one ordered pair?
(-11, -7), (-1, -3), (4, -1), (19, 5)
What is a possible equation in Point-Slope Form?
y + 7 = 2/5 (x + 11)

13. Wrap Up Point-Slope Form Graph Using Point-Slope form
Start at the point
Graph the slope
Write equation in point-slope form
Given a point and a slope
Given two points
Writing an equation from a table
Find the rate of change (slope)
Pick a point to plug in
HW: P. 255 #1-53 EOO, #67-71 odd
DLUQ: What two things are given to you in the point-slope form?