ramtype">int</td><td class="paramname">$scale</td><td>[optional] </td></tr>
  </table>
  </dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>string the square root as a string, or <b>NULL</b> if <em>operand</em> is negative. </dd></dl>
<dl class="section since"><dt>Since</dt><dd>4.0 </dd>
<dd>
5.0 </dd>
<dd>
7.0 </dd></dl>

</div>
</div>
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