Well, the directions in which I will actually hit my circle are all the directions in the righthalf of a plane.
与圆有交点的方向,是在平面右半部分的全部方向。
2
So, let's say that I'm going to look first at what happens if I'm in the righthalf of a plane of a blackboard, so, in the yz plane.
我们看看先发生了什么,如果黑板是yz平面上的右半平面。
3
The value function turns out to be continuous in the whole plane, and is even continuously differentiable in the interiors of both right and left half planes.