# -*- coding: utf-8 -*-
# 请定义一个函数quadratic(a, b, c)，接收3个参数，返回一元二次方程 ax^2+bx+c=0的两个解
import math
def quadratic(a,b,c):
        x1 = (-b + math.sqrt((b * b) - (4 * a * c))) / (2 * a)
        x2 = (-b - math.sqrt((b * b) - (4 * a * c))) / (2 * a)
        return x1,x2

print('quadratic(2,3,1) = ' , quadratic(2,3,1))
print('quadratic(1,3,-4) = ' , quadratic(1,3,-4))
if quadratic(2,3,1) != (-0.5, -1.0):
    print('测试失败')
elif quadratic(1,3,-4) != (1.0, -4.0):
    print('测试失败')
else:
    print('测试成功')