title: Unexpected result from a division
body: <p>I tried to implement the following calculation:</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  #include &lt;math.h&gt;
  
  int main(){
  
      float sum = 0;
      int c = -4;
      float x1 = 136.67;
      float x2 = 2.38;
  
      sum = c / (pow(abs(x1 - x2), 2));
      printf("%f %f %f",sum,x1,x2);
  
      return 0;
  }
  </code></pre>
  
  <p>But the value of <code>sum</code> after the execution turns out to be -4. What is wrong?</p>