Python3小练习1——（ax*x+ bx + c = 0的解）

import math

def quadratic(a,b,c):
    if b*b-4*a*c<0:
        return "无解"
    elif a==0:
        return -c/b
    else:
        return (-b+math.sqrt(b*b-4*a*c))/a/2,(-b-math.sqrt(b*b-4*a*c))/a/2

s1=quadratic(1,3,-4)
print(s1)

s2=quadratic(1,1,1)
print(s2)

s3=quadratic(1,4,4)
print(s3)

s4=quadratic(1,5,4)
print(s4)