Square Roots in Scala

session.scala

object session {
  	
  def sqrt(x: Double) = {
    def abs(x: Double) = if (x < 0) -x else x
  
    def sqrtIter(guess: Double): Double =
      if(isGoodEnough(guess)) guess
      else sqrtIter(improve(guess))
	  	
    def isGoodEnough(guess: Double): Boolean =
      abs(guess * guess - x) / x < 0.001
	  	
    def improve(guess: Double) =
      (guess + x / guess) / 2
  
    sqrtIter(1.0, x)
  }                                               //> sqrt: (x: Double)Double
  
  sqrt(2)                                         //> res0: Double = 1.4142156862745097
  sqrt(4)                                         //> res1: Double = 2.000609756097561
  sqrt(1e-6)                                      //> res2: Double = 0.0010000001533016628
  sqrt(1e60)                                      //> res3: Double = 1.0000788456669446E30
}