1. The problem statement, all variables and given/known data There is a circuit diagram which I can't post atm and don't think it's relevant to my question. Also: R1 =R2=10k and C=.1μF And: Find V(t) 2. Relevant equations We're given the equation V(t)=1/RC ∫t-∞ Vi(t)e-(t-τ)/RCdτ My problem is I don't recall what tau is here "τ" and I'm not sure what I should be using for the Vi(τ). I've been trying to find it in my notes and physics textbooks but I can't seem to find it. LOL I must be stuck on stupid because I know I've seen these and am familiar with them. If anyone has this book and has solved this problem please help me out. :D 3. The attempt at a solution Found V(t) by Thevenin Analysis to be .5Vi also used Thevanin to find Req=20K to replace the 1/R in the integral. Not sure what else to do.