1. The problem statement, all variables and given/known data I'm a bit confused about how to find the phase equation of a lossy low pass filter eg. 2. Relevant equations For a normal low pass filter it's just arctan(wRC) 3. The attempt at a solution So im comparing this by subbing in values and comparing to a bode plot of an actual circuit on a breadboard and a spice version of the circuit. But this is nothing like what i get in spice, i've checked for errors but I think its something wrong with the way im actually calaculating it... but cant figure out why?