Shifting Operation !!

Discussion in 'Homework Help' started by Anthony Quah, Mar 13, 2008.

  1. Anthony Quah

    Thread Starter Active Member

    Dec 1, 2007
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    I am doing Electronic Signal System, I got confuse how to obtain the formula of Shifting Operation ..from reference book "Continuous and Discrete Signals and Systems" by Samir S. Soliman pg. 10

    i dont know how x(t) come out with t + 1 and -t + 3 ... i know the result of the shifting..but i dont know what make t + 1 and -t + 3 in the formula... would desperate need some help ... :-(


    the attachment will give more detail about it...hoping to get some help..


    Humble student,
    Anthony
     
  2. Colin Mac

    Member

    Mar 11, 2008
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    When t is -1, x(t) is -1+1 = 0
    when t is 0, x(t) is 0+1 = 1

    When t is 2, x(t) is -2+3= 1
    and when t is 3, x(t) is -3+3 = 0
     
  3. Anthony Quah

    Thread Starter Active Member

    Dec 1, 2007
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    i know that...but how we come out with the formula t+1 and -t+3 which extract from the graph ( in the attachment) ?
     
  4. Colin Mac

    Member

    Mar 11, 2008
    18
    0
    You're not been clear. Are you asking where t+1 and -t+3 come from? There is no formula in that attachment.
     
  5. Anthony Quah

    Thread Starter Active Member

    Dec 1, 2007
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    pls refer my first post...it consist of the graph..and by my ideal..it should able to generate formual t + 1 and -t + 3...i just want to know how to digest the graph in order to get those 2 formual.. ^^
     
  6. Colin Mac

    Member

    Mar 11, 2008
    18
    0
    x(t) = t + 1, at t = -1 to 0
    I've explained how in post 2
     
  7. Anthony Quah

    Thread Starter Active Member

    Dec 1, 2007
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    thank colin..kinda need time to digest it ^^
     
  8. Colin Mac

    Member

    Mar 11, 2008
    18
    0
    Ok. It's not difficult. Look at it this way.
    Looking at the graph, you can already see that x(t) = 0 when t is -1.

    Another way to say that; x(t) = t + 1 when t is -1.
    Why? Substitute -1 in for t:

    x(t) = t + 1
    x(t) = -1 + 1
    x(t) = 0

    **
    Now find what x(t) is when t = 0 by putting 0 in for t, then look at the graph.
     
  9. Anthony Quah

    Thread Starter Active Member

    Dec 1, 2007
    80
    0
    lol...i wish i was a mathematic genius...i look into it...thanks again for detail explaination... :)
     
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