1一些记号和预备知识首先.对于三维欧式空间!3的一组不共面的向量e_1,e_2,e_3,我们可以唯一以其作为一组基底构造仿射坐标系.记g_(ij)=e_i·e_j,由于内积的交换性,故e_i·e_j=e_j·e_i,亦即g_(ij)=g_(ji),i,j∈{1,2,3}.由此诱导的度量系数矩阵 1 Some tokens and preliminary knowledge First of all, for a set of non-coplanar vectors e_1, e_2, e_3 in the three-dimensional European space!3, we can construct the affine coordinate system uniquely using it as a set of bases. Note g_(ij)=e_i E_j, due to the commutativeness of the inner product, e_i·e_j=e_j·e_i, that is, g_(ij)=g_(ji),i,j∈{1,2,3}. matrix