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).
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.