一元二次方程求根

import math   
a = eval(input())
b = eval(input())
c = eval(input())
delta = pow(b,2)-4*a*c   
if a == 0:
    if b == 0:
        print('Data error!')
    else:
        print(-c/b)
else:
    if delta < 0:     
        print('该方程无实数解')
    elif delta == 0:
        x = (math.sqrt(b*b-4*a*c)-b)/(2*a)
        print(x)
    elif delta > 0:
        x1 = (math.sqrt(b*b-4*a*c)-b)/(2*a)  
        x2 = (-math.sqrt(b*b-4*a*c)-b)/(2*a)
        if x1 > x2:    
            print('{} {}'.format(x1,x2))
        else:
            print('{} {}'.format(x2,x1))