pan class="bmw">See 14.4: 1-6 for more practice. Don't use
      the formulas in the chapter, rather practice using matrix
      multiplication. The formulas are just a way of writing matrix
      multiplication without writing down the matrices, and only
      work for functions from $\RR^n\to\RR$. Our matrix
      multiplication method works for any function from
      $\RR^n\to\RR^m$.</span><span class="larsonfive">See Larson
      13.5:1&ndash;6 for more practice (you can check answers in the
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