6.15 z-TRANSFORM OF an cos(nω)u(n)

Let x1(n) = cos (nω)u(n). Now we can write

 

image

 

The given expression is x(n) = ancos (nω)u(n) = anx1(n)
∴ X(z) = Z[anx1(n)]

 

Using scaling property, we can write

 

image

 

Hence, the obtained z-transformation pair is

 

image

Get Signals and Systems now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.

Start your free trial