11.5 Finding The Slope of a Line

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11.5 Finding The Slope of a Line
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Slopes are commonly associated with mountains.
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The slope we are studying is associated with the
graph of a line.
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Definitions of Slope

• The tilt or inclination of a line
• The ratio of vertical change to horizontal
  change.
• The change in y over the change in x

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Tilt or Inclination
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Vertical ChangeHorizontal Change

• This ratio is also known as
• Rise
• Run

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How many points do you need to draw a line?

• One
• Two
• Three

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Graph (3,2) and (-1,-1)
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Draw a line through the points.
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Now that we have our line lets find its slope.
Remember we are finding the following
ratio Vertical or Rise
Horizontal Run
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Vertical Changeor the Rise
3
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Horizontal Changeor the Run
4
3
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Vertical Rise Horizontal
Run

• 3
• 4

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Find the slope of the following line.
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The slope is

• 1
• 2

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Find the slope of the line.
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The slope is.

• -3

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Find the slope of these lines.
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The slope is

• Black line 3
• Red Line 1
• Blue Line -1/2
• Which one is the steepest?

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Find the slope of these lines
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The slope is

• Orange line 0
• Green Line Undefined

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Can you find the slope of a line without graphing
it?

• Of course you can.
• How?

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Find the slope of the line containing the points
below.

• 1. (2,5), (0,5)
• 2. (3,4), (4,3)
• 3. (0,-2), (3,7)
• 4. (0,-1), (1,-7)

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11.6 Slope Intercept Form
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Slope Intercept Form
y mx b
slope
y-intercept
Slope Intercept Form is another name for Function
Form. Y is COMPLETELY alone!
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Identify the Slope and Y-Intercept
y 2x 6
m 2
b 6
y 3x - 2 2
m 3 2
b - 2
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Identify the Slope and Y-Intercept
-3x 3y 6
3y 3x 6
y x 2
b 2
m 1
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Identify the Slope and Y-Intercept
2x - 5y 10
-5y -2x 10
y 2x - 2 5
b - 2
m 2 5
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Graphing Slope Intercept Form
y 2x 1 3
m 2 b 1 3
Remember slope is rise over run
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Graphing Slope Intercept Form
y 3x - 2
m 3 b -2
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Graphing Slope Intercept Form
y -x - 3 3
m -1 b -3 3
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Graphing Slope Intercept Form
5x - 2y 4