AC Waveform Question: Deriving Vrms from Vpk - Fawzi

[Fawzi Da]

Hello everyone

I would like to ask a question that seems simple but can't find the (detailed) proof/ how its derived.
Simply we know that Vrms = Vpk /[Sqrt (2)]. But how is that derived?

Thank you in advance
Fawzi

 

[Averagesupernova]

That is only correct for a true sine wave.

 

[meBigGuy]

RMS for a sinewave
http://www.rfcafe.com/references/electrical/sinewave-voltage-conversion.htm

More about RMS in general
https://en.wikipedia.org/wiki/Root_mean_square