And I don't like that negative sign in the mean.

而且我不喜欢这个号。

See any circles with two negative signs?

看到任何带有两个号的圆圈吗？

Anyway, this is all just to say that the change in potential energy is negative F times the change in position.

的F(力的大)位置变化量有号是因为 你让这个力一直推着你。

Well I will now magically separate the negative sign from the 4. 1, 2, abracadabra.

好吧，我现在将神奇地将号与 4. 1, 2, abracadabra 分开。

If they don't, draw a plus on the three unmarked coins if they're heavier or a minus if they're lighter.

他们不这样做， 则在三枚未标记的硬币上画一个加号， 它们更重，或它们更轻， 则画一个号。

Now it is negative 1 time 4. With multiplication you can detach and reattach positive or negative signs from the number.

现在它是数 1 4。通过法，您可从数字中分离并重新附加正号或号。

This value – the charge of a single electron in Coulombs – is known as the elementary charge, and it's denoted with a lowercase " e" .

一个号。这个值，值 一个电子的电荷，库仑为单位，你知道。

So plus X times the negative expected value of Y. So I'll just say minus X times the expected value of Y. And that negative sign comes from this negative sign right over here.

所加上 X Y 的预期值。所我只说 X Y 的预期值。号来自这里的号。

Now, if you want to calculate the magnifying power of the telescope, just start with the same equation you used for the magnifying lens, but with a negative sign, because the image is flipped.

现在，你想计算望远镜的放大倍率，只需从用于放大镜的相同方程开始， 但要加上一个号， 因为图像是翻转的。

Which means that the induced emf in a coil of wire is equal to the number of coils, times the change in magnetic flux over the change in time, all multiplied by a negative sign.

这意味着线圈中的感应电动势为 等于线圈数磁通量随时间变化的变化，全部号。

Geometrically, the meaning of this function is that for any input vector X-Y-Z, you consider the parallelopyped defined by this vector, V and W, then you return its volume with a plus or minus sign, depending on orientation.

几何上 这个函数的意义是 对于任何输入向量X-Y-Z 你考虑由这个向量V和W定义的平行体 然后你返回它的体积 根据方向带正号或号。