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Homework Help: Recursive Rule Question

  1. Feb 16, 2010 #1
    1. The problem statement, all variables and given/known data

    I need to find the recursive and explicit formulas for the sequence 1,-2, 3, -4, 5

    2. Relevant equations

    Recursive Rule: Fn= Fn-1 + Fn-2
    Explicit Rule: position of terms F1, F2, F3,....

    3. The attempt at a solution

    I have figured out explicit because its ((-1)^n+1)n

    Recursive rule i am having trouble with because its around something like -(Fn-1 +1) or close to that
  2. jcsd
  3. Feb 16, 2010 #2
    Re: Help finding the Recurisve rule for this Sequence

    Let a(n) be nth term. You should be able to say what a(1) is. Now manipulate the expression for a(n+1) until you have a right side that depends of a(n), a(n-1), etc.
  4. Feb 16, 2010 #3


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    Homework Helper

    the sign of the added one will change depdneding on whether n is odd or even
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