Phép biến đổi Z:

\(f\left. it \right.=\sum_{i=0}^{∞} f(t)δ(t-it)\)

\(f\left. t \right.=\sum_{i=0}^{∞} f(t)δ(t-it)\)

\(f\left. it \right.=\sum_{i=0}^{∞} δ(t-it)\)

\(f\left. it \right.=\sum_{i=-∞}^{∞} f(t)δ(t-it)\)