Square root with recursion

sqrt.js

function sqrt(original, rootn) {
  if (rootn < 1) return;

  rootn = rootn || (original - 1);

  var isSqRoot = (rootn * rootn) === original;

  while (isSqRoot === false) {
    return sqrt(original, rootn - 1);
  }
  console.log(rootn);
  return rootn;
}

console.log(sqrt(9) === 3);
console.log(sqrt(4) === 2);
console.log(sqrt(100) === 10);
console.log(sqrt(10) === 10);