title: Undefined reference to sqrt (or other mathematical functions)
body: <p>I have this simple code:</p>
  
  <pre><code>max = (int) sqrt (number);
  </code></pre>
  
  <p>and in the header I have:</p>
  
  <pre><code>#include &lt;math.h&gt;
  </code></pre>
  
  <p>But application still says undefined reference to <code>sqrt</code>. Do you see any problem here? It looks like everything should be okay.</p>