What is the mathematical symbol for the period of a wave?

Answer 1

The symbol used is usually t, for time. The SI unit for time is a second, so s may also be used.

I also think that freq. as for frequency and any of the mathematical notations for time, minute, second, etc. hertz is a term for frequency which was once universally cycle or kilocycle, megacycle now referred to a kilohertz, megahertz, etc.

So time would be notated according to the theory being used. Radio frequencies, pulse frequencies, data frequencies...