3. The following block diagram shows a complex control system with two feedback loops and two disturbance variables. Ge! 5 62 G is Gaz Gal Note that for simplify: Ysp = Y(8), is a transfer function which goes the same for other notations. Find the closed-loop transfer of Y'(s)/Y"(s) in a simplified form using: i) General expression (UZ) (5 marks) ii) Derivation method (12 marks) (Total: 17 marks)