title: Php precision with floating point - complex equation = 1
body: <p>I have the following equation</p>
  
  <blockquote>
    <p>1 - ((.5 * 0.83333333333333) ^ 2 + (.5 * 0.83333333333333) ^ 2 + (.5 * (1 - 0.83333333333333)) ^ 2 + (.5 * (1 - 0.83333333333333)) ^ 2) </p>
  </blockquote>
  
  <p>In Php5, this results in an answer of 1 as opposed to .63 (on two machines, OSx and Centos).  Should I be exclusively using the bc math functions of Php to do equations like this?</p>