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

但让来说说正弦、余弦和对数函数。

I get it! Sin is opposite hypotenuse... Yes.

懂了，正弦是对边比斜边。是。

I actually write it with these little ridges in it, so SOH... CAH... TOA.

写时候会写成这种三角形状，这是正弦，余弦，正切。

We draw them as sine waves, as if something's going back and forth or up and down.

把它画成正弦波，就好像有东西在前后或上下动。

So we generate this swept sine wave and we use that to capture the acoustic of the cave.

生成这个正弦扫频信号，然后利用它来测定洞穴声音特性。

But that sine wave is just gonna be a tremendous load on all the health care providers.

但这个正弦波对所有医务工作者来说都是巨大工作量。

I'm gonna use sine of theta, oh sorry, sine of phi.

要使用正弦 theta， 哦抱歉，正弦 phi。

So each of the x sine in the sample.

所以样每个 x 正弦。

Here is a pure 261 hertz sine wave.

这里是一个纯261赫兹正弦波。

Sine theta equals opposite over hypotenuse.

正弦θ等于对边除以斜边。

You should learn how to use the sine bar .

你应该学习如何使用正弦规。

And now for the Y direction we can use the definition of sine of theta.

现在对于 Y 方向，可以使用正弦函数定义。

I don't have the slightest idea what sine and cosine mean.

根不知道正弦和余弦是什么意思。

We're picking up our old ECS example project, the sine wave of cubes.

正在使用旧 ECS 示例项目，立方体正弦波。

I thought the x-direction used  cosine and the y-direction used sine?

以为 x 方向使用余弦而 y 方向使用正弦？

We're going to be moving our mass of cubes using a sine wave.

将使用正弦波移动大量立方体。

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

这是三角学，上边 以及跨正弦和余弦角度。

First of all, electromagnetic waves do not travel in a single direction in a sinusoidal fashion like this.

首先，电磁波不会像这样以正弦方式沿单一方向传播。

The force of gravity parallel equals mass times gravitational field strength  times the sine of the incline angle.

平行重力等于质量乘以重力场强度乘以倾斜角正弦值。

This means that the circumference of the band should  be 2 pi times the sine of that angle.

这意味着带周长应为 2 pi 乘以该角度正弦值。