A tunable capacitor (with variable capacitance) is charged by a U

0=12 V battery and then is connected in parallel to
a R=3 Ω resistor. The capacitance
C(t) of the capacitor
is controlled so that the current in the circuit remains constant at all times. What is the power (external) in Watts needed to keep the current in the circuit constant? Note that one possible way of controlling the capacitance could be varying the distance between the plates of the capacitor which, in general, requires some work.

2 answers

from the internet: W = V^2 / R

12v Battery -> C(t) and 3ÃŽ© R in parallel -> back to battery

so the resistor and the capacitor are in parallel and you want to know the overall resistance so you can figure out the power needed? well this website gives some suggestions...but it's physics over my head. if it looks familiar go for it.
i can't post links so just google resistors-and-capacitors-in-parallel and the first link should be the one i saw
i dun get it :(