Try this specific example and work it out exactly by both methods. Do you get the same answer, or different answers? In general, the average power is not equal to the average voltage times the average current. There may be special cases where it is true, but not in general. Do you feel this is a special case where it is true? If it is, you can try the functions and see if it works. But, why deal with this complication if you don't need to.Once again, I offer my thanks, Steve.
Please have a look on the attachment. If there is any confusion, please let me know so that I can clarify it. You might also need to have a look on this diagram from my previous post. Please help me. Thanks.
With best regards
PG