If you go back to your trigonometry, That's another example where knowing the trigonometry is very helpful.

回顾一下学过的三角函数,这个例子再次佐证了熟知三角函数是多么有用

耶鲁公开课 - 基础物理课程节选

If you don't know how to measure anything, you are doing algebra and trigonometry.

如果你不知道如何进行测量,你就是在研究代数或者三角函数了

耶鲁公开课 - 基础物理课程节选

You can square this guy and add it to the square of this guy and you will find, using the magic of trigonometry, that this is true.

你可以把这两个式子平方相加,再用一下三角函数的性质,你会发现这是正确的

耶鲁公开课 - 基础物理课程节选

Trigonometry functions you know all the time.

三角函数必须随时会用

耶鲁公开课 - 基础物理课程节选