For the following mechanisms, assume the motion of link 2 to be the known input. (a) write the vector loop equations and indicate the fixed constants (knowns), variables (unknowns), and constraints if there's any (with the corresponding constraint equations), (b) find the Jacobian matrix of mechanism. 1: 2: 3 3 1 1 1 + 3: 4 1 + 2 TI 1 4: 2 3 4 D G 1