import math

def equacio_2_grau(a, b, c):
    discr = b * b - 4 * a * c
    if discr > 0:
        s = 'dues reals'
    elif discr == 0:
        s = 'una doble'
    else:
        s = 'complexes'
    return s


def arrels_reals(a, b, c):
    discr = b * b - 4 * a * c
    return discr >= 0


def calcula_arrels(a, b, c):
    discr = b * b - 4 * a * c
    if discr < 0:
        return 0, 0, 0
    elif discr == 0:
        return 1, -b / (2 * a), 0
    else:
        x1 = (-b + math.sqrt(discr)) / (2 * a)
        x2 = (-b - math.sqrt(discr)) / (2 * a)
        if x1 > x2:
            x1, x2 = x2, x1
        return 2, x1, x2