1. The problem statement, all variables and given/known data Im trying to find the uncertainty for a log function. I have that f = 20log(V_in/V_out) and i want to know (delta)f 2. Relevant equations f = 20log(V_in/V_out) 3. The attempt at a solution I was going to do it the calculus way: f = 20log(V_in) -20log(V_out) df = 20*f*[(dV_in/V_in) - (dV_out/V_out)] but this doesn't seem right to me. I've never seen subtraction in an error calculation before. And im not sure if this is a relative error or a percent error. I want a relative error (with units), the only problem is that my function has no units, soI'm not sure what I should do in that case (if that makes sense). Is there another simple formula for log function errors?