1. The problem statement, all variables and given/known data When a camera flashes, the batteries begin recharging the flash capacitor which stores the charge Q according to the function Q(t) = Q* (1-e-t/a) where t is the elapsed time in seconds since the camera flash and Q* and a are non-zero (a) What does Q* represent? (b) Find the inverse of this function (c) How long does it take to recharge the capacitor to 90% if a = 5? 2. Relevant equations 3. The attempt at a solution I said that Q* was the constant of proportionality, but I'm not sure how right that is. My attempt at the inverse came out as t*a/ln(Q*) = Q I'm wondering if my answer for (a) is at all correct, and where to go from here, I have no idea how to attempt (c) and I think my answer to (b) is wrong.