  $x=3$.</li>

      <li>Draw a graph of $f(x)$ and the tangent line on the same
      axes. Place a dot at the point $(3,9)$ and label it on your
      graph. Place another dot on the tangent line up and to the
      right of (3,9). Label the point $(x,y)$, as it will represent
      any point on the tangent line.</li>

      <li>Using the two points $(3,9)$ and $(x,y)$, compute the
      slope of the line connecting these two points. Your answer
      should involve $x$ and $y$. What is the rise (i.e, the