值错误：Python 中的数学域错误
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Value Error: math domain error in Python
提问by sirius_pain
I'm writing a code to help me solve the Pythagorean theorem in Python. Problem is, I keep getting this one error when I have the code try solving for B.
我正在编写代码来帮助我解决 Python 中的勾股定理。问题是，当我让代码尝试解决 B 时，我不断收到这个错误。
This is the bit that always gives me problems:
这是总是给我带来问题的一点：
bsqr = (int(c) ** 2) - (int(a) ** 2)
b = int(bsqr) / sqrt(bsqr)
I get this error:
我收到此错误：
Traceback (most recent call last):
File "<pyshell#24>", line 1, in <module> pythag()
File "C:\Python34\fact.py", line 156, in pythag
b = int(bsqr) / sqrt(bsqr)
ValueError: math domain error
What is causing this error, and how can I fix it?
是什么导致了这个错误，我该如何解决？
采纳答案by mgilson
It's likely because bsqris negative and taking the sqrt of a negative number doesn't work too well.
这可能是因为它bsqr是负数，并且取负数的 sqrt 效果不佳。
>>> import math
>>> math.sqrt(-1)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: math domain error
Check your algebra/inputs. c(the hypoteneuse) should alwaysbe bigger than either of the legs (aand b)
检查您的代数/输入。 c（斜边）应始终大于任何一条腿（a和b）
Also, side note, you could also get a ZeroDivisionErrorif you happen to put in values for aand cwhich are equal (after inttruncates them).
另外，请注意，ZeroDivisionError如果您碰巧输入了a和c相等的值（在int截断它们之后），您也可以获得 a 。
