107 Inverse Variation

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10-7 Inverse Variation
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Inverse Variation

• y k/x
• y varies inversely as x

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Example 1

• Suppose y varies inversely as x when x 80, y
  2. Find y when x 16.

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What is another way to write y k/x

• We can write this same equation without the
  fraction as xy k
• Is this true for the last example?

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Example 2

• If the tension on a violin string is constant,
  the frequency of a note varies inversely as the
  length of the string. When the length of a
  violin string is 75cm the frequency is 512Hz.
  What length do we want a string to be that
  produces a frequency of 640Hz?

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Example 3

• What about a frequency of 328Hz from the previous
  example?

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Inverse Square Variation

• y or

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Example 4

• The intensity of light varies inversely as the
  square of the distance from the source. At a
  distance of 8ft. from the source a light meter
  measures an intensity of 24units. How many units
  will you have at a distance of 32ft?

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Example 5

• Try these 5 Pg. 415

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Classwork

• Pg 416 1-13, 16-19