Determine which of the following digital transfer functions are physically realizable.

Gc(z) = 10(1 + 0.2z- 1 + 0.5z- 2 )

· z- 1 + z- 2 + 1.5z-3 1 5 -1 -2 G() .z -z c z = · 1 + z- 1 + 2z- 2 G (z)- z+l.5 c - z 3 + z2 + z + 1 G ( ) = z- 1 + 2z- 2 + 0.5z- 3 c z 1 2 z- +zGc(z) = 0.1z + 1 + z- 1 Gc(z) = z- 1 + z- 2 Problem