1. The problem statement, all variables and given/known data Hi, I have a quick question about applying the RC time constant formula for a lab report. In the lab, we charged a capacitor to 20 V and then let them discharge, recording the voltage every 10 seconds, up to 240 sec. Now I was asked to graph the time vs. voltage in excel, fit an exponential trendline and obtain an equation. 2. Relevant equations The equation I got from my line is: y = 19.89e-0.02x My lab manual gives the time constant formula as V = V0e-1/t , with t being the time constant. I have to use the experimentally obtained equation to calculate the time constant. 3. The attempt at a solution I see the V0 is very close to 20, so that makes sense, but I don't understand how to combine the two equations to get the time constant. It seems that V should be the final voltage, but I have 24 values, all of which would give a different x. I'm confused how to proceed from here.