def quadratic(a,b,c):
    delta=b**2-4*a*c
    if a==0:
        if b==0:
            print('a=0, b=0, no solution')
        else:
            return (-b)/c
    else:
        if delta<0:
            print('delta<0',delta)
        elif delta==0:
            x=(-b)/(2*a)
            return x
        else:
            x=(-b+math.sqrt(delta))/(2*a)
            y=(-b-math.sqrt(delta))/(2*a)
            return x,y