I have a function f(t), if this function has only one harmonic frequency then its time averaged can be calculated in straight forward manner. But suppose if it has two frequencies whose corresponding time period are $T_1$ and $T_2$, how will I calculate the time average?
If suppose $T_1>T_2$, will I calculate the time average with $T_1$, as this is a longer time scale.
Is this concept correct??