Is the Z-Transform of sin(Bn) Really Zero?

  • Thread starter Thread starter jpm
  • Start date Start date
  • Tags Tags
    Z-transform
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
1 reply · 2K views
jpm
Messages
3
Reaction score
0

Homework Statement



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

[tex]x(n)=sin(Bn)[/tex]

Homework Equations

The Attempt at a Solution



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

[tex]x(n)=sin(Bn)u(n)+sin(Bn)u(-n-1)[/tex]

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?
 
Physics news on Phys.org
Remember that [tex]sin x = \frac {e^{jx}-e^{-jx}}{2j}[/tex]