Keith Dysart wrote:
The expression you really mean is

Pavg = Vrms * Irms * cos(A)

Yep, that's what I meant.

No. I mean multiply the instantaneous value by
the instantaneous value, ...

It is not clear to me what physical meaning, if any,
can be attached to such a product.
--
73, Cecil http://www.w5dxp.com