Great common dividor

gcd.scala

object sqrtTest extends App
{
    def sqrt(x: Double) =
    {
        def sqrtIter(guess: Double): Double =
        {
            if(isGoodEnough(guess)) guess
            else sqrtIter(improve(guess))
        }
        def improve(guess: Double) =
            (guess + x / guess) / 2

        def isGoodEnough(guess: Double) =
            abs(square(guess) - x) < 0.001

        def abs(value: Double) = if(value < 0) -value else value

        def square(value: Double) = value * value

        sqrtIter(1.0)
    }

    println(sqrt(2))
    println(sqrt(3))
    println(sqrt(4))
    println(sqrt(10))


}