Given the following circuit:
I'm trying to find the equivalent capacitor assuming that the capacitors are already charged. I'm aware that C1 and C2 are in parallel, therefore they must have the same voltage. What I'm not too sure about is if I can just add both of their capacitance since the resistance R is only connected to C2, but at the same time C2 instantly affects C1 keeping the voltages equal.
Just to clarify, by equivalent capacitor I'm referring to this: