WarmUp

1
Warm-Up

• Simplify the Following Equations
• 32 / 48
• -15 / 20
• 24 / -30
• -13 / 13
• -13 / -13

2
4.4 The Slope of a Line

• Goals
• How to find the slope of a line using two of its
  points
• How to interpret slope as a constant rate of
  change or an average rate of change
• Why You Ask
• You can use slope to represent the rate of change
  of one quantity with respect to another, such as
  distance traveled compared to time used

3
Finding the Slope of a Line

• The SLOPE of a nonvertical line is the number of
  units the line rises or falls for each unit of
  horizontal change from left to right.

• The slope of the nonvertical line passing through
  the points (x¹, y¹) and (x2, y2) is
• m y2 - y¹
• x2 - x¹

4
Working with Ordered Pairs

• Find the slope of the line passing through (-2,
  0) and (3, 1)
• Find the slope of the line passing through (-1,
  2) and (2, 2)
• Find the slope of the line passing through (0, 0)
  and (1, -1)
• The Slope of a Vertical Line is Not Defined
• Find the slope of the line passing through (0, 0)
  and (0, -1)

5
Classification of Lines by Slope

• A line with a positive slope rises from left to
  right. (mgt0)
• A line with negative slope falls from left to
  right. (mlt0)
• A line with slope zero is horizontal. (m0)
• A line with undefined slope is vertical. (m
  is undefined)