Well, you know the normal vector.

那么当然知道它的法向量。

That corresponds to normal vector pointing up.

那相当于法向量指向上。

The normal vector would be the gradient of g,you see.

法向量就会是g的梯度。

The normal vector pointing up,here we know what it means.

法向量指向上，这里我们知道它是什么意思。

K instead of using the vertical vector k, you use the normal vector i.

你用了法向量i，而不是竖直向量。

First of all, what does the normal vector to a cylinder look like?

先思考一下圆柱面的法向量？

So, for a sphere, the normal vector is divided by the radius of the sphere.

关于球体，法向量是,除以球的半径。

And, we've seen that when you put the equation of a plane in the form ax by cz = d, well, in there is actually the normal vector to the plane, or some normal vector to the plane.

我们可以这样看平面方程,它以等式ax+by+cz=d，的形式表示，实际上，是该平面的法向量，是它的某个法向量。

In particular, counterclockwise means that the normal vector will be going out of the region.

逆时针旋转意味着,法向量是指向区域外的。

And, we know how to find a normal vector to this plane just by looking at the coefficients.

我们已经知道,如何根据系数找到这个平面的法向量。