import?math
def?quadratic_equation(a,?b,?c):
????x=pow(b,2)-4*a*c
????t=math.sqrt(x)
????if?x>=0:
????????x1=-b/(2*a)+t/(2*a)
????????x2=-b/(2*a)-t/(2*a)
????????x3=(-b?+?t)?/?(2?*?a)
????????x4=(-b?-?t)?/?(2?*?a)
????????return?x1,x2,x3,x4
print?quadratic_equation(2,?3,?0)

為什么x1！=x3 ， x2！=x4