# -*- coding: utf-8 -*-

import math

def quadratic(a, b, c):
    delta = b*b - 4*a*c
    if delta == 0:
        return (-b+math.sqrt(delta))/(2*a)
    elif delta > 0:
        return ((-b+math.sqrt(delta))/(2*a), (-b-math.sqrt(delta))/(2*a))
    else:
        return

quadratic(2, 3, 1)
quadratic(1, 3, -4)