python - 我除以零但没有提示 "ZeroDivisionError"

Question

所以我使用二次方程来产生实根。root1 和 root2

当我除以零时，让A = 0

两个根分别是0.0和-0.0

这应该给出错误:ZeroDivisionError

这是我的代码:

import math
A = float( input( "\nEnter the coefficient A: " ) )

B = float( input( "\nEnter the coefficient B: " ) )

C = float( input( "\nEnter the coefficient C: " ) )

print( "\nThe coefficients of the equation:\n" )
print( "  Coefficient A = ", A )
print( "  Coefficient B = ", B )
print( "  Coefficient C = ", C )

root1 = -B + math.sqrt(B**2 - (4*A*C)) / 2*A  
root2 = -B - math.sqrt(B**2 - (4*A*C)) / 2*A


print( "\nThe roots of the equation:\n" )
print( "  Root #1 = ", round(root1,3) )  
print( "  Root #2 = ", round(root2,3) )

if A = 0 , B = 4.5, C = 8

输出为:

The roots of the equation:

  Root #1 =  -4.5
  Root #2 =  -4.5

Answer 1

Python就像数学，操作系统的顺序将使它除以2而不是乘以A，要改变它，像数学中那样做括号，也在您的所有操作 -B 丢失:

(-B + math.sqrt(B**2 - 4*A*C)) / (2 * A) 

或者除以两次:

(-B + math.sqrt(B**2 - 4*A*C)) / 2 / A