For the simplest context in which one can motivate a vector and also motivate the rules for dealing with vectors, is when you look at real space, the coordinates x and y.

对于最简单的情况,我们能用矢量,以及相关的规则来处理的,是实空间,x-y 坐标系

耶鲁公开课 - 基础物理课程节选

I ask when y=0, then I say 0=15+10t-5t^.

我问何时y=0,然后得到0=15+10t-5t^

耶鲁公开课 - 基础物理课程节选

So we're talking about an experiment when you generate-- Each experiment generates both an x and a y observation and we know when x is high, y also tends to be high, or whether it's the other way around.

这里说的是由试验产生的,每一次试验可以获得一组x与y的观察值,当x值大的时候,y值可能也大,或者相反

耶鲁公开课 - 金融市场课程节选

When I call this class definition, it calls init, init and I give it an x and a y value.

我说过，当我们，调用这个类的定义的时候，它会去调用。

麻省理工公开课 - 计算机科学及编程导论课程节选

And what we see here is now when we're combining the p, we have our 2 p x and our 2 p y orbitals that are lower in energy, and then our pi anti-bonding orbitals that are higher in energy.

这里我们看到,当我们结合p轨道时，在低能处我们有,2px和2py轨道，π反键轨道在更高的能级处。

麻省理工公开课 - 化学原理课程节选

When does it hit the ground" is "When is y=0"?

何时落地"也就是"何时位移为零"

耶鲁公开课 - 基础物理课程节选

If when x is low, y also tends to be low, then this will be negative number and so will this, so their product is positive.

如果x取值小,同时y值也小,这将是一个负值,这个也是负值,负负得正,结果是正值

耶鲁公开课 - 金融市场课程节选

When t is equal to 10,000 years or 10,000 seconds, you're going to find y is some huge negative number.

当t为一万年或一万秒时,我们得到y是一个极大的负数

耶鲁公开课 - 基础物理课程节选

So, in that notation, I want to ask, when is y=0?

那么这个情况下,我问你们,什么时候y=0

耶鲁公开课 - 基础物理课程节选

If they tend to move together, when x is high and y is high together at the same time, then the covariance will tend to be a positive number.

如果x和y同向变动,当x值和y值同时都很大,协方差的结果将会是一个正值

耶鲁公开课 - 金融市场课程节选