Find an expression for $$H$($z$)$ as a ratio of two

polynomials of z $($Hint: let r$1=$ $+$ j and

p$1=$ $+$ j and substitute values after find$-$

ing common denominator for $$H$($z$).)$ Find the

poles and zeros of $$H$($z$).$ If poles or zeros are

complex, express them in polar form. Deter$-$

mine whether or not the system is stable and

briefly justify why.