13.6.2  Inverse Z-transform of a rational function

The inverse Z-transform of a rational expression is a formula for the general term of a sequence with the given rational expression as its Z-transform. The invztrans command finds the inverse Z-transform of a rational expression.

• invztrans command takes one mandatory and two optional arguments:
  • rat, a rational expression.
  • Optionally, x the variable (by default x).
  • Optionally, n, a variable to be used by the result (by default x).
• ztrans(rat ⟨,x,n ⟩) returns the inverse Z-transform of rat.

Examples

since ztrans(1) yields x/x−1.