Calculating the average power dissipated in an AC circuit
Negative power in a resistor? Where did I go wrong?


The load is not a resistor. If it were a resistor, there would be no phase difference between the current and voltage waveforms.

In general, a negative power is possible --- it means the load has a power source within it and it is delivering power back to your source rather than taking power from it.

So I don't think you have approached the problem incorrectly.