Бэк КВур

from math import *
def kvyr(a,b,c):
    d = ((b ** 2) - (4 * a *c))
    if a == 0:
        return "kirill hyesos"
    elif d > 0:
        x1 = (- b + sqrt(d)) / (2 * a)
        x2 = (-b - sqrt(d)) / (2 * a)
        return x1, x2
    elif d == 0:
        x = - b / (2 * a)
        return x
    else :
        return "error"


print(kvyr(1,4,1))