Whenever I introduce a new topic involving vectors, I want you to 1st think about an arrow, and specifically think about that arrow inside a coordinate system, like the X-Y plane, with its tail sitting at the origin.

每当我介绍一个涉及向量的新话题时 我希望你们首先想到一个箭头 特别是一个坐标系中的箭头 比如X-Y平面 它的尾部位于原点。