But let me go back to these sines, cosines and logarithms.

但让我们再来说说正弦、余弦和对数函数。

Here I'm only showing cosines for simplicity.

在这里， 为了简单起见，我只显示余弦。

How is knowing cosines gonna help you with your backstroke?

学会余弦对仰泳有什么帮助？

It's all just trigonometry, connecting sides and angles through sines and cosines.

这是三角学，上边 以及跨正弦和余弦的角度。

So, the law of cosines is an extension of the pythagorean theorem to the arbitrary angles...

所以余弦定律是勾股定理对任意角度的延伸。

So, for example, I don't think that being a math person means that you can recite the formulas between the sines, cosines, tangents and to use logarithms and exponentials interchangeably.

所以，比如，我认为成为数学家不是指你要能背诵正弦、余弦、正切的函数公式和转化运用对数和指数。