Skip to main content\(\newcommand{\sech}{\textrm{sech}}
\newcommand{\csch}{\text{csch}}
\newcommand{\reals}{\mathbb{R}}
\let\ds\displaystyle
\newcommand{\integral}[3][]{\int#1 #2 \;d#3}
\newcommand{\dsintegral}[3][]{\ds\int#1 #2 \;d#3}
\newcommand{\lt}{<}
\newcommand{\gt}{>}
\newcommand{\amp}{&}
\definecolor{fillinmathshade}{gray}{0.9}
\newcommand{\fillinmath}[1]{\mathchoice{\colorbox{fillinmathshade}{$\displaystyle \phantom{\,#1\,}$}}{\colorbox{fillinmathshade}{$\textstyle \phantom{\,#1\,}$}}{\colorbox{fillinmathshade}{$\scriptstyle \phantom{\,#1\,}$}}{\colorbox{fillinmathshade}{$\scriptscriptstyle\phantom{\,#1\,}$}}}
\)
