onvert $\frac{xy}{x^2+y^2}$ to polar coordinates (i.e.,
      a function of $r$ and $\theta$). As $(x,y)$ approaches the
      origin, what does $r$ approach? Take the limit of your polar
      coordinate function as $r$ approaches that value and
      interpret your result.</li>
    </ol>
  </div>
                <p>In all the examples above, we considered
  approaching a point by traveling along a line. However, even if a
  function has a consistent limit along every line, that is not
  enough to always g