 3\sin t)$, which means $x=2\cos t$ and $y=3\sin t$.

    <ol>
      <li>At the point $\vec r(t)$, we'd like a formula for the
      temperature $f(\vec r(t))$. What is the temperature of the
      horse at any time $t$? [In $f(x,y)$, replace $x$ and $y$ with
      what they are in terms of $t$.]</li>

      <li>Compute $df/dt$ (the derivative as you did in
      first-semester calculus).</li>

      <li>Construct a graph of $f(t)$ (use software to draw this if
      you like). From your graph, at what time