推知的英文：
1.to derive from; to infer

参考例句：

Infer a motive from an effect
从效果推知动机。

The judge inferred a motive from an effect
法官从结果中推知动机。

If you see a doctor leaving a house, you may deduce (the fact) that someone in the house is ill.
如果你看见一个医生从某家出来，你就可以推知这家有人病了。

derive是什么意思：
v. 源于，来自；得到，导出；（从…中）提取

Something derived;a derivative.
派生派生物；导出物

derivation; descendent
派生物

This is a derivative word.
这是一个衍生词。

Esters are named as derivatives of the acids from which they are derived
酯是作为相应的酸的衍生物来命名的。

We will replace the partial derivative by an ordinary derivative.
我们可用普通微商代替偏微商。