Python数学运算的一个小算法（求一元二次方程的实根）详解编程语言

 1 #!/usr/bin/env python 
 2 # -*- coding: utf-8 -*- 
 3 import math 
 4 def quadratic(a,b,c): 
 5     if a == 0: 
 6         raise TypeError('a不能为0') 
 7     if not isinstance(a,(int,float)) or  not isinstance(b,(int,float)) or not isinstance(c,(int,float)): 
 8         raise TypeError('Bad operand type') 
 9     delta = math.pow(b,2) - 4*a*c 
10     if delta < 0: 
11         return '无实根' 
12     x1= (math.sqrt(delta)-b)/(2*a) 
13     x2=-(math.sqrt(delta)+b)/(2*a) 
14     return x1,x2 
15 print(quadratic(2,3,1)) 
16 print(quadratic(1,3,-4))