\ifx\pdfunknown\relax
 \WARMprocessMMAR{QA1}{eps}{mbb}
\else
 \WARMprocessMMAR{QA1}{pdf}{mbb}
\fi
 \renewcommand{\xyWARMinclude}{\scaledfig{.7}}
\begin{xy}
 \xyMarkedImport{}
% \xyShowMarkPoints{*[red]@{x}}{-}
 \xyMarkedPos{3sinX},*+++!L{3\sin x}
 \xyMarkedPos{sin3X}*++{}
  ,\ar@{<-}+(.7,-1)*+!U!L(.4){\sin 3x}
\end{xy}