import mathdef quadratic(a, b, c):    if b**2-4*a*c<0:        return '该方程无实根'    elif b**2-4*a*c==0:        return -b/(2*a)    else:        no1=(-b+math.sqrt(b**2-4*a*c))/(2*a)        no2=(-b-math.sqrt(b**2-4*a*c))/(2*a)        return no1,no2a=float(input('请输入非0二次项系数a:'))b=float(input('请输入一次项系数b:'))c=float(input('请输入常数c:'))print(quadratic(a, b, c))