Question Three A control system is given by the general feedback loop shown in Figure 2 in which G(s) is: 1 G(s) = $ +1 Determine: (a) the value of k required to attain a steady state error of 0.75 for a step input of 9 numerical units (5 marks) (b) the gain cross-over frequency for the resulting loop gain in rad/s (7 marks) (c) the phase margin (8 marks) X(s) Y(s) K G(s) Figure 2.General feedback loop