\input epsf
\nopagenumbers
\magnification=\magstep1

\noindent {\bf Problem statement} Evaluate the iterated integral
$\displaystyle {\int_{0}^{2}\int_{-x}^{x}(2+x)\, dy\, dx}$ in three
ways:

\noindent a) Directly.

\medskip

\noindent b) By reversing the order of integration (that is,
converting to a double integral and then expressing the double
integral as one or a sum of iterated integrals in $dx\,dy$ order)
and finally, computing the result.

\medskip

\noindent c) Changing to an integral in polar coordinates and
computing the result.

\vfil\eject\end