3.3 Find Slope and Rate of Change

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3.3 Find Slope and Rate of Change

• Objective Students will be able to find the
  slope of a line and interpret slope as a rate of
  change

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Definitions

• Slope- a ratio of the change in the y-coordinates
  to the change in the x-coordinates. Shows how
  steep a line is.
• Rate of Change- a ratio that describes how much
  one quantity changes with respect to a change in
  another quantity

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Slope

• Symbol m
• m Rise change in y
• Run Change in x
• Form m y2- y1
• x2 x1
• (x1,y1) , (x2,y2)

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Find the Slope of the Line
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Positive Slope

• m 0 line rises from left to right

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Find the Slope of the Line
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Negative Slope

• m lt 0
• line falls from left to right

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Find the Slope of the line that passes through
the points
(-3,-1) and (2,-1)
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Slope of Zero

• m 0 Horizontal Line

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Find the slope of the line that passes through
the points
(-2,4) and (-2,-3)
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Undefined Slope

• m undefined
• Vertical Line

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List the 4 Ways we can classify the slope of a
Line

• Positive

Negative
No Slope
Undefined
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Rate of Change
Rate of change Change in y Change in
x
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Rate of Change

• Use the table to find the rate of change. Then
  explain its meaning.

Number of computer games Total Cost(s)
x y
2 78
4 156
6 234
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Find the Rate of Change

• The table shows the cost of using a computer at
  an internet café for a given amount of time.
  Find the rate of change in cost with respect to
  time.

Time (hours) 2 4 6
Cost (dollars) 7 14 21
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Given the Slope find the missing coordinate
(x, 4), (6,-1) m 5 6
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Given the slope find the missing coordinate
(1,3), (9,y) m 3 4
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Given the Slope Find the Missing Coordinate
(4,3), (x,7) m -2 (-4,r),(-8,3) m-5