>>> from arrels import arrel_quadrada

---- inici

>>> a = arrel_quadrada(2, 0.01)
>>> round(a, 6)
1.414216

>>> a = arrel_quadrada(2, 0.0001)
>>> round(a, 6)
1.414214

>>> a = arrel_quadrada(25, 0.0001)
>>> round(a, 4)
5.0

---- fi

>>> a = arrel_quadrada(168, 0.0001)
>>> round(a, 4)
12.9615

>>> a = arrel_quadrada(65, 0.01)
>>> round(a, 6)
8.06226

>>> a = arrel_quadrada(65, 0.001)
>>> round(a, 6)
8.062258