ee Larson 13.5:7&ndash;10
      for more practice.</span>
    </div>
      Suppose $z=f(s,t)$ and $s$ and $t$ are functions of
    $u$, $v$ and $w$. Use the chain rule to give a general formula
    for $\partial z/\partial u$, $\partial z/\partial v$, and
    $\partial z/\partial w$.
  </div>

  <div class="review">
    If $w=f(x,y,z)$ and $x,y,z$ are functions of $u$ and $v$,
    obtain formulas for $\dfrac{\partial f}{\partial u}$ and
    $\dfrac{\partial f}{\partial v}$. 
      <div class="review-answer"