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Homework Help: Rational Function Application Question

  1. Mar 8, 2010 #1
    1. The problem statement, all variables and given/known data
    A home security system costs $9/month in electricity costs (you may assume this is a fixed cost over the duration of the time involved in this question). A new security system costs $1500 to purchase and lasts for 8 years.

    Determine a rational function that gives the annual cost of a security system as a function of the number of years you own the system. Using this function determine the average annual cost of the security system given above.


    2. Relevant equations
    n/a

    3. The attempt at a solution
    I got C(x)=(1500+108n)/n, where n is the number of years.
    What would be the "average annual cost" of the security system given above?
     
  2. jcsd
  3. Mar 9, 2010 #2

    tiny-tim

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    Hi Cuisine123! :wink:
    That is the "average annual cost", isn't it? :smile:
     
  4. Mar 9, 2010 #3
    The questions says, "Determine a rational function that gives the annual cost of a security system as a function of the number of years you own the system. Using this function determine the average annual cost of the security system given above."

    C(x)=(1500+108n)/n, where n is the number of years, would be the rational function that gives the annual cost of the security system.

    What about the average annual cost of the security system given above ?
    Would it be C(8)=(1500+108(8))/8?
     
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