1. The problem statement, all variables and given/known data This problem was given in my physics test, and my physics teacher was unable to provide me with an answer for it. Given a circuit made up of a generator of variable frequency, i=Im(sin2∏ft-∅) and voltage u=Um(sin2∏ft), capacitor of capacitance 1μF, resistor of resistance 120Ω, and a coil of inductance 0.06H with negligible resistance. We were asked to find the expression of Im^2 in terms of Um and f using the law of addition of voltages, and by taking the values of time as 0 and 1/(4f). 2. Relevant equations Uc=q/C U of coil = Ldi/dt Ur=Ri 3. The attempt at a solution I was unable to think past finding the law of addition.