Python实现一元二次方程的解

# -*- coding: UTF-8 -*-
__metaclass__=type
import math

#一元二次方程求解x^2+2x+1=0
def yiyuan_jie(a,b,c):
    delta=b*b-4*a*c
    if delta<0:
        return u'无解！'
    try:
        if delta==0:
            return -(b/(2*a))
        if delta>0:
            squart_delta=math.sqrt(delta)
            x1=(-b+squart_delta)/(2*a)
            x2=(-b-squart_delta)/(2*a)
            return '{:.2f} {:.2f}'.format(x1,x2)
    except ZeroDivisionError:
        print u'分母不能为零！'
if __name__=='__main__':
    print yiyuan_jie(5,8,1)