Z-transform results • X1(z)=1+2z−1+5z−2X_1(z) = 1 + 2z^{-1} + 5z^{-2}X1(z)=1+2z−1+5z−2 • X2(z)=3z−1+4z−3X_2(z) = 3z^{-1} + 4z^{-3}X2(z)=3z−1+4z−3 Why finite sequences have “nice” ROC • Z-transform ...