When a camera flash goes off, the batteries immediately begin to recharge the flash’s capacitor, which stores electric charge given by Q(t) = Qo(1 – e –t/a)
(The maximum charge capacity is Qo and is measured in seconds.)
(a) Find the inverse of this function and explain its meaning.
(b) How long does it take to recharge the capacitor to 90% of capacity if a =2?