Lesson 6-9: Variation

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Lesson 6-9 Variation

• Objective
• Students will
• Find the constant of variation and setup direct
  and inverse variation equations
• Use variation equations to solve problems

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Direct Variation Equations or Why
direct? Take or , where k
2 If y goes up, x must go up y and x move the
same ? direct k is the constant of variation
must stay constant
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Inverse Variation Equations or Inverse ?
opposite ? if y goes up, x must go down
Choosing Identify the variables Ask if the one
value increases, what will the other
do? increase also ? direct decrease ? inverse
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Example 1 The force applied to a spring causes
the length to increase. 8 pounds makes the
spring 4 inches. Find k and write a general
equation.
Which type of variation? Direct What would be the
x variable? y? x pounds y inches
What would be the length if the weight is 20lbs?
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• Example 2
• Time (t) required to do a job varies inversely
  with the number of people working. It takes 4hrs
  for 12 people to put up bleachers. Write the
  equation to represent the problem.
• How long would it take 3 people to do the same
  job.

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Marker Board pg 283-284

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• Assignment/6-9/283-284/3-27M3,34-42e

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