Graphing Equations

1
Graphing Equations

• Using Slope-Intercept Form

2
Review of Slope
The slope of a line is a measure of its
steepness. The steeper the line the greater the
magnitude of the slope
Slope 4
Slope -4
Slope 1
Slope 1/4
Slope -1/4
Slope -1
3
The Y-intercept
By definition in mathematics the intercept, as
used in the coordinate plane, is the distance
from the origin ( 0, 0) to the point where a
function touches an axis. For the y-intercept it
would be where the line touches the y axis.
( 0, 7)
Notice how the y coordinate of the y-intercept is
the same as the distance from the origin
7
The y-intercept is 7
What is the y-intercept of the red line?
2
-5
What is the y-intercept of the blue line?
4
Slope-intercept Form of a Linear Equation
Slope- intercept form is written
where
m is the slope of the line
and b is the y-intercept
Give the slope and y-intercept for
Slope 2
Y-intercept -7
5
Now You Try
Slope-intercept Form Slope Y-intercept






3
6
-4
-2
1
1
-5
0
0
1
6
Graphing in Slope-intercept Form
Given an equation in slope-intercept form
Run 1
Rise 3
Step 1 Plot the y-intercept
Step 2 Write the slope as rise over run
Step 3 Starting from the y-intercept apply the
slope and plot points on either side of the
y-intercept
Rise -3
Run -1
Step 4 Connect the points with a line
7
You Try
Graph the following equations
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2
8
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9
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10
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11
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