英语语法分析

Well, now we have a relation between dx and dz.

从而我们就可以得到dx和dz的关系。

So we found an expression for dz in terms of dx and dy.

我们得到了dz关于dx和dy的表达式。

What we really want to do is express df only in terms of dz.

我们想要的仅仅是。