Root mean square
= Root mean square
{title2=$x_{\rm rms}=\sqrt{\langle x^2\rangle}$}
{wiki}
The root mean square of a real function or data set is the <square root> of its mean square. A sinusoid of amplitude $a$ has root mean square $|a|/\sqrt2$. For orthogonal or uncorrelated zero-mean components, the squared root mean square of their sum is the sum of their mean squares; this follows by expanding the square and observing that all cross terms average to zero.