I'm not too sure what you mean by comparing the polarity.
From the diodes, I only know that if D1 is on (and D2 is off), V1=Vi and V2<Vi. If D2 is on (and D1 is off), V2=Vi and Vi<V1. If both are off, V2<Vi<V1. I can sub in Vi but I don't know any other V(t) input I can use in regards to the...
Compute V3(t)-V4(t). The capacitors are initially discharged, the voltage source is turned on at t = 0, and the diodes’ forward voltage drop is negligible (Vf = 0). What is the value of V3(10s) – V4(10s)?