1. Unit 2 Day 3: Graphing Using Slope-Intercept Form
Essential Questions: What is the slope-intercept form of a line? How do we use it to graph the line?

2. Vocabulary
y-intercept: the point (0 , y) where an equation crosses the y-axis, represented with the letter b
Slope-Intercept Form: y = mx + b
m = slope
b = y- intercept

3. y-intercept: (0 , 1) y-intercept: (0 , 2)
Example 1: Identify the y-intercept from each of the graphs.
y-intercept: (0 , 1)
y-intercept: (0 , 2)

4. y-intercept: (0 , -5) y-intercept: (0 , 0)
Example 2: Identify the y-intercept from each of the graphs.
y-intercept: (0 , -5)
y-intercept: (0 , 0)

5. y-intercept: y-intercept: c. y = x - 2 d. y = x - 13 Slope: Slope:
Example 3: Identify the slope and the y-intercept in each equation.
a. y = 4x b. y = -x - 3
Slope: Slope:
y-intercept: y-intercept:
c. y = x d. y = x - 13
Slope: Slope: 4 -1
(0 , 2)
(0 , -3) 1 2 1 2 1
(0 , -2)
(0 , -13)

6. Graphing Using y = mx + b Plot the y-intercept as your first point.
To get your other points, count out the slope from the y-intercept in both directions. Remember, a whole number as a slope ALWAYS has a “run” of 1!
Slope
y-intercept

7. Example 4: Graph each line using y = mx + b.
y = -2x + 3
Slope:
y-intercept: -2 1
(0 , 3) 3 2
y = x - 4
Slope:
y-intercept: 3 2
(0 , -4)

8. Example 5: Graph each line using y = mx + b.
y = 3x - 5
Slope:
y-intercept: 3 1
(0 , -5) 2 3
y = x + 4
Slope:
y-intercept: 2 3 -
(0 , 4)

9. Example 6: Graph each line using y = mx + b.-2 1
2x + y = 4 Slope:
y-intercept:
-2x
-2x
y = -2x + 4
(0 , 4) 2 3
3y - 2x = 6 Slope:
y-intercept:
+2x
+2x
3y = 2x + 6 3 3 3
(0 , 2)
y = x + 2 2 3

10. Summary
Essential Questions: What is the slope-intercept form of a line? How do we use it to graph the line?
Take 1 minute to write 2 sentences answering the essential questions.