M3.ptx

<exercise>
  <statement>
      <p>Explain why the matrix <m><xsl:value-of select="name"/>=<xsl:value-of select="matrix"/></m> is or is not invertible.</p>
  </statement>
  <answer>
      <xsl:choose>
          <xsl:when test="invertible"><m><xsl:value-of select="name"/></m> is invertible.</xsl:when>
          <xsl:otherwise><m><xsl:value-of select="name"/></m> is not invertible.</xsl:otherwise>
      </xsl:choose>
  </answer>
</exercise>