1.- The block diagram of a linear control system is shown in the Fig., where r(t) is the reference input and n(t) the disturbance. a) Is the system stable or unstable. Justify your answer. b) What is the system type? c) Find the steady-state value of e(t) when n(t)=0 and r(t)=ts(t). d) Find the conditions on the values of and K so that the solution is valid. e) Find the steady-state value of y(t) when r(t)=0 and n(t)=us(t)