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Basic Member
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同個網站有不太一樣的看法，供大家參考。
在這個網站上有人問了一個問題，ab/xy應該是a*b/x*y還是(a*b)/(x*y)。
http://mathforum.org/library/drmath/view/54341.html
直接挑文章的結論來看好了。
引用:
So to answer your question, I think both answers can be considered
right - which means, of course, that the question itself is wrong. I
prefer the standard way (your first answer) when talking to students,
unless their own text gives the "implicit multiplication first" rule;
but in practice if I came across that expression, I would probably
first check where it came from to see if I could tell what was
intended. The main lesson to learn is not which rule to follow, but
how to avoid ambiguity in what you write yourself. Don't give other
people this kind of trouble.
- Doctor Peterson, The Math Forum
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以下為無責任翻譯
所以回答你的問題，我想兩種答案都是可以被視為正確的，因為這題目本身就有問題。不過如果要回應學生的疑問，除非他們看的課本還是參考書籍有定義，不然我覺得以標準的運算方法來教導學生(即a*b/x*y)會比較好。但是在實務上，我如果遇到這樣的問題，我會去看這問題是怎麼來的，最後才來判斷。其實討論這個課題，不僅是去看有沒有規則可以去遵循，也是在告訴我們不要寫出模稜兩可的東西。那是會帶給別人困擾的。
彼得森 博士 於數學論壇。 |