% This file is public domain \begin{defproblem}{sample} \begin{onlyproblem} Differentiate $y=\sin x$ \end{onlyproblem} \begin{onlysolution} $y'=\cos x$ \end{onlysolution} \end{defproblem} \begin{defproblem}[1]{sample2} \begin{onlyproblem} Differentiate $y = \sin(#1x)$ \end{onlyproblem} \begin{onlysolution} $y'=#1\cos #1x$ \end{onlysolution} \end{defproblem} \begin{defproblem}{sample3} \begin{onlyproblem} Differentiate $y = x^2$. \end{onlyproblem} \begin{onlysolution} $y' = 2x$ \end{onlysolution} \end{defproblem}