\input epsf
\nopagenumbers
\magnification=\magstep1

\noindent {\bf Problem statement} Does either of these improper double
integrals converge? If not, explain why. If yes, evaluate. Explain
your answers.

\medskip

\noindent a) $\displaystyle {\int\!\! \int_{{\bf R}^2}e^{-\vert x
\vert - \vert y \vert} \, dA}$ \qquad 
b) $\displaystyle {\int\!\! \int_{{\bf R}^2}e^{-\vert x + y \vert} \,
dA}$

\vfil\eject\end