Math Help - RC-Circuit

a) The current in a wire is defined as the derivative of the charge: I(t)=Q'(t). The quantity of charge Q in coulombs (C) that has passed through a point in a wire up to time t (measured in seconds) is given by Q(t)=Qmax(1-(e^((-1/RC)t))). At what time is the charge the maximum charge, Qmax? At what time is the charge minimum? Determine limQ(t).

To find when , we may set:



Now, solve for .