Find the range of values of <i>x</i> for which


                  


<br clear="all" /><table border="0" width="100%"><tr><td>
<table align="center"><tr><td nowrap="nowrap" align="center">
 &#8730;<i>x</i>+ </td><td nowrap="nowrap" align="center">
&#x00A0;1
<div class="hrcomp"><hr noshade="noshade" size="1"/>&#8730;<i>x</i><br /></td><td nowrap="nowrap" align="center">
 &#x003C;  4 </td></tr></table>
</td></tr></table>




where &#8730;<i>x</i> is the positive root.