poluoren回答了该问题
2019-10-05 11:16
这是我写的一小段代码 > begin{equation} begin{aligned} bm{A}_{-k}=left(&underbrace{0quadcdotsquad 0}_{k-1}quad k(1-alpha^2)alpha^kquad-(k+1)(1-alpha^2)alpha^kquadunderbrace{0quadcdotsquad 0}_{N-1}right. \ &left....