calibcant/overview.tex: Fix 'formula' -> 'formulas' typo

Wikipedia says that both 'formulas' and 'formulae' are acceptable
plural forms [1], but I have a few 'formulas' occurences in here
already.

[1]: http://en.wikipedia.org/wiki/Formula

diff --git a/src/calibcant/overview.tex b/src/calibcant/overview.tex
index cd420146287da04d07f4a115b46274b034f1102e..dcd0ec7db4512c605367d8ef447602651d137ed2 100644 (file)
--- a/src/calibcant/overview.tex
+++ b/src/calibcant/overview.tex
@@ -109,7 +109,7 @@ where $x_0$ sets the center and $\Gamma$ sets the width of the curve.
 However, the correct \PSD\ for a damped harmonic oscillator in a white
 noise bath is given by \cref{eq:psd-Vp}\citep{burnham03,benedetti12}.
 
-These formula are fundamentally different.
+These formulas are fundamentally different.
 
 For example, the slope of \cref{eq:psd-Vp} is zero at $f=0$, as we can
 see by using the chain rule repeatedly,