1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Z Transform

  1. Oct 10, 2009 #1


    User Avatar

    1. The problem statement, all variables and given/known data

    I'm trying to take the (two-sided, aka defined for all n) Z-transform of


    2. Relevant equations

    3. The attempt at a solution

    What I tried to do was split x(n) into


    The Z transform of the first part of x(n) was found from a table. The z transform of the 2nd was found from the fact that the z transform of [tex]-sin(Bn)u(-n-1)[/tex] equals the z transform of [tex]sin(Bn)u(n)[/tex]

    [tex]X(z)=\frac{z sin(B)}{z^2-2zcos(B)+1}-\frac{z sin(B)}{z^2-2zcos(B)+1}[/tex]

    So the z transform is zero? Could this be?
  2. jcsd
  3. Oct 10, 2009 #2


    User Avatar

    Remember that [tex]sin x = \frac {e^{jx}-e^{-jx}}{2j}[/tex]
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook