4.1 Graphing Equations in Slope-Intercept Form

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4.1 Graphing Equations in Slope-Intercept Form
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Investigation

• In groups, you will investigate slope and
  y-intercepts using graphing calculators

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Discussion

1. What happens to m when the graph is less steep
   than y x?
2. Does changing the value of m cause the line to
   curve or become something other than a straight
   line?
3. Does changing the m change the y-intercept?

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• 4) How does addition or subtraction change b?
• 5) Does changing the b affect the steepness of
  the graph?
• 6) Does changing the b determine whether the
  graph is positive or negative?
• 7) Does changing the b cause the graph to become
  curved or another figure?

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Slope-Intercept Form

• y mx b
• What is the m?
• What is the b?

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• Write the equation in slope intercept form and
  then graph.
• Slope ¼, y-intercept -1
• Slope 4, y-intercept 3

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• Graph 4y 5x 8

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• Graph 3x 2y 6

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Graph y -7
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Which of the following is an equation in
slope-intercept form for the line shown in the
graph?
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• The ideal maximum heart rate for a 25-year-old
  exercising to burn fat is 117 beats per minute.
  For every 5 years older than 25, that ideal rate
  drops 3 beats per minute.
• A. Write a linear equation to find the ideal
  maximum heart rate for anyone over 25 who is
  exercising to burn fat.

B. Graph the equation.
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• C. Find the ideal maximum heart rate for a
  55-year-old person exercising to burn fat.