1. Lesson 4.4
Objective: To graph a line on a coordinate plane only using the slope and the y-intercept.
Essential Question: How can I graph an equation without making a table?
y = mx + b
y-intercept
Slope
Slope: the slant of the line. Rise over the run
y-intercept: The location where the line crosses the y-axis

2. EXAMPLE 1 m = 1 m = -3 m = 0 m = -1 m = -2 b = 2 b = -4 b = 3 b = 0
Writing equations in slope-intercept form
Equation Slope y-intercept
m = 1
m = -3
m = 0
m = -1
m = -2
b = 2
b = -4
b = 3
b = 0
b = 6
y = 1x + 2
y = -3x – 4
y = 0x +3 or y = 3
y = -x + 0 or y = -x
e) 2x + y = 6
Rewrite (subtract 2x)
-2x x
y = -2x + 6

3. EXAMPLE 2 Find the slope and the y-intercept Plot the y-intercept
Graphing Using Slope and y-intercept
Graph the equation y = 2x + 4
Find the slope and the y-intercept y
m =2 or b = 4 1
Plot the y-intercept 2
Use slope to plot second point x
Draw a line through the two points

4. EXAMPLE 3 You try it Graph the equation y = 3x - 1
Find the slope and the y-intercept y
m =3 or b = -1
Plot the y-intercept
Use slope to plot second point 1
Draw a line through the two points x 3

5. EXAMPLE 4 You try it Graph the equation
Find the slope and the y-intercept
m = b = 2 y
Plot the y-intercept
Use slope to graph second point
Draw a line through the two points -2 x 3

6. EXAMPLE 5
Graphing y = b
Graph y = 2 y x y -3 2 4
y = 2 x

7. EXAMPLE 6
Graphing x = a
Graph x = -3 y x y -3 -2 3
x = -3 x

8. What is the slope in the video example? What is the y-intercept?
What's the first point you graph when graphing from slope intercept form?

9. Summarize how to graph an equation without making a table first.