import math

print("Ввод абсц:")
a=float(input("a="))
b=float(input("b="))
c=float(input("c="))
d=float(input("d="))
print(Cardano(a,b,c,d))


def Cardano(a, b, c, d):
    if a == 0:
        return 0
    res = []
    p = (3 * a * c - b * b) / 3 * a ** 2
    q  = (2 * math.pow(b, 3) - 9 * a * b * c + 27 * a * a * d) / 27 * math.pow(a, 3)
    D = (q / 2) ** 2 + (p / 3) ** 3

    if D < 0:
        if q < 0:
            fi = math.arctg(math.sqrt(-D))
        elif q > 0:
            fi = math.arctg(math.sqrt(-D)) + math.pi
        else:
            fi = math.pi / 2
        y1 = 2 * math.sqrt(-p / 3) * math.cos(fi / 3)
        y2 = 2 * math.sqrt(-p / 3) * math.cos(fi / 3 + 2 * math.pi / 3)
        y3 = 2 * math.sqrt(-p / 3) * math.cos(fi / 3 + 4 * math.pi / 3)
        res.append(y1 - b / 3 * a)
        res.append(y2 - b / 3 * a)
        res.append(y3 - b / 3 * a)

    return res


print(Cardano(1, 6, 3, -10))