A certain second$-$order discrete$-$time system has the following frequency response with sampling period Ts $=130$ seconds. a$)$ Determine the dc gain of the system. b$)$ Find the response of the system if the input is cos$($k$/2).$ c$)$ The transfer function of the system has two zeros at the same location. What is the location of the zeros? d$)$ The system acts as a highpass filter since it attenuates low frequencies and passes high frequencies. Find the passband of the system, which is the range of frequencies $($in Hz$)$ for which the amplitude is attenuated by no more than $25\%.$