1. The problem statement, all variables and given/known data Find the Thevenin equivalent network of the lattice network (see attached), viewed from points As and Br (terminals Bs and Ar are not connected to anything). 2. Relevant equations 3. The attempt at a solution Without the resistance f, the problem is quite simple. I can find voltages at nodes Bs and Ar as a function of voltage between As and Br (potential dividers). Then insert f and check how it modifies the impedance? I think it only works to check the Thevenin impedance between Bs and Ar, not As and Br, but I'm not sure. Any help would be appreciated.