zài / wēi / jī / fēn / zhōng / wǒ / men / cháng / yòng / wú / xiàn / xiǎo / de / biàn / huà / lái / yán / jiū / hán / shù / de / xìng / zhì

在微积分中，我们常用无限小的变化来研究函数的性质。

In calculus, we often use infinitesimal changes to study the properties of functions.