gistfile1.hs

-- Derivada numerica en x0 con paso h
-- http://en.wikipedia.org/wiki/Numerical_differentiation
derivada :: (Double -> Double) -> Double -> Double -> Double
derivada f x0 h = (f (x0 + h) - f x0) / (2*h)

newton :: (Double -> Double) -> Double -> Double
newton f x0 = do
	let x1 = x0 - (f x0 / (derivada f x0 0.01))
	if abs (x1 - x0) < 0.001 then x1 else newton f x1

function :: Double -> Double
function x = x^2-4