Newton's Square Root Approximation

gistfile1.txt

def abs(x)
  (x < 0) ? -x : x
end

def sqrtIter(guess, x)
  isGoodEnough(guess,x) ? guess : sqrtIter( improve(guess,x) ,x)
end


def isGoodEnough(guess,x)
  abs(guess * guess - x) < 0.001
end

def improve(guess,x)
  (guess + x / guess) / 2
end

def sqrt(x)
  sqrtIter(1.0,x)
end