>>82
> dy/dx これが分数ならdy over dx
> ですが、実際の読み方はdy dxです。
>
Wikipediaによると、どちらの読みもするようですよ
https://en.wikipedia.org/wiki/Derivative
(The above expression is read as "the derivative of y with respect to x",
| "d y by d x", or "d y over d x".
| The oral form "d y d x" is often used conversationally,
| although it may lead to confusion.)