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How to represent this discrete function?

  1. Mar 22, 2015 #1
    1. The problem statement, all variables and given/known data

    my function: [itex]sin\frac{N\pi}{2}[/itex] , N = 1, 2, 3, ...

    N = 1 ---> f(N) = 1
    N = 2 ---> f(N) = 0
    N = 3 ---> f(N) = -1

    2. Relevant equations


    3. The attempt at a solution

    [itex]-\frac{1}{2}(-1)^N[/itex]

    obviously it's wrong but just an 'attempt'

    my book refers to the substitution N=2k-1 where k=1, 2, ...
    but i don't understand how this returns the correct values.

    any thoughts?
     
  2. jcsd
  3. Mar 22, 2015 #2

    LCKurtz

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  4. Mar 22, 2015 #3

    SammyS

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    I suspect that "N=2k-1 where k=1, 2, ... " is simply a portion of the solution given by your book.

    Which values of N are given by these values of k ?

    By The Way: You need to state the problem to be solved, in the body of you post - - a complete statement - - regardless of the title of the Thread.
     
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