MAT 150 Unit 16

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MAT 150 Unit 16

• Ch 9 2
• Alternate Methods of Graphing Linear Equations

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Graphing by Intercepts

• Youve probably noticed that almost all lines
  (except horizontal and vertical lines) will cross
  the x axis and the y axis. These crossing
  points are referred to as the intercepts.

y-intercept ?
x-intercept
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Graphing by Intercepts

• From the previous graph observe
• The y-intercept is the point where the line
  crosses the y-axis, or (0, 2). Note that the
  value of x at the y-intercept is always 0.
• The x-intercept is the point where the line
  crosses the x-axis, or (2, 0). Note here that
  the value of y is always 0.
• If we could find the intercepts we could easily
  draw the line through the two points.

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Graphing by Intercepts

• 2x 3y 6
• To find the x-intercept remember that y 0, so
  substitute 0 for y and solve 2x 3(0) 6
• 
  2x 6
• 
  x 3 (3, 0)
• To find the y-intercept remember that x 0, so
  substitute 0 for x and solve 2(0) 3y 6
• 
  3y 6
• 
  y 2 (0, 2)

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Graphing by Intercepts

• So the intercepts are (3,0) and (0, 2)

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Graphing Lines

• x 2y 2
• x-intercept, y 0
• x 2(0) 2
• x 2 (2, 0)
• y-intercept, x 0
• 0 2y 2
• 2y 2
• y 1 (0, 1)
• Draw the line