I would like you to know the easiest inverse trig functions, but not much.

我想让你们了解最简单的反三角函数，但不需要了解太多。

youdao

That is actually not a good way to do it, because if I put sufficiently complicated trig functions in there then you might not be able to see that two terms are the same. Take an easy one.

这不是一个很好的办法，因为如果函数足够复杂，你可能就不会看出，这两项是相同的，举个简单例子。

youdao

And they are free. "Introduction to Trigonometry is where I teach people about the trig functions."

VOA: standard.2010.03.26