The capacitors question says:
A capacitor is charged through a resistor
The cell has e.m.f. 1.50 V and negligible internal resistance.
The capacitor is initially uncharged. The time constant of the circuit is 100 s.
The switch is closed at time t = 0.
What is the potential difference across the capacitor at time t = 200 s?
The answer is 1.30V, which uses the formula V = V0 e^(-t/CR).
However, as the capacitor is being charged, I thought the p.d. across it is given by V = V0 (1 - e^(-t/CR))
Can somebody explain why the discharging equation is used in this case?