title: Quickly calculate reciprocal of large numbers in JavaScript?
body: <p>Is it quicker to do:</p>
  <pre><code>const reciprocal = denominator =&gt; 1.0/denominator
  </code></pre>
  <p>Or</p>
  <pre><code>const reciprocal = denominator =&gt; Math.pow(denominator, -1) //or denominator**(-1)?
  </code></pre>
  <p>Or some other trick?</p>
  <p>The denominator is a large (~1e50) integer (in fact it's a factorial) and I need to do lots of similar calculations (roughly 6e5 times).</p>