title: How do i get Math.Sqrt to return a Bignum and not a Float?
body: <p>I'm trying to calculate the square root of a really big number in Ruby. The problem I have is that the Math.sqrt function looks like this</p>
  
  <p><code>sqrt(numeric) → float</code></p>
  
  <p>If I feed it a really big number, it will give me FloatDomainError: Infinity.</p>
  
  <p>What is the best way to get <code>sqrt()</code> to return a BigNum? Is there perhaps a gem for this or will I have to write my own function to calculate the square root? </p>
  
  <p>In that case, what is the easiest way to go about doing this? Taylor series? The square roots of the numbers will <em>always</em> be integers.</p>