1. The problem statement, all variables and given/known data The expression entering the upper terminal (It is an ideal basic circuit element) is: q = 1/α2 - (t/α +1/α2)e-αt C Find the maximum value of the current entering the terminal if α = 0.03679 s-1 2. Relevant equations 3. The attempt at a solution This is an example in my book that I need to understand to be able to to my homework, but I have no idea whats going on. Here is the solution: i = dq/dt i = 0 - [(1/α +1/α2)e-αt(-α) +e-αt(1/α)] Why did they subtract from 0? i = -e-αt[-t -1/α +1/α] i = te-αt Current at max if di/dt=0 How do you know the current is at max at 0? di/dt = te-αt(-α) + e-αt = 0 e-αt(1-αt) = 0 t = 1/α At this point I understand that they substituted for t in this equation to get the answer 10 Amps Any help is greatly appreciated!