三对角行列式:一个三对角矩阵的非零系数在主对角线上,或比主对角线低一行的对角线上,或比主对角线高一行的对角线上。
形如这样的矩阵就叫三对角行列式:
WBR|* WBR * WBR 0 WBR WBR 0 WBR WBR 0 | WBR
WBR |* WBR * WBR * WBR 0 WBR WBR 0 | WBR
WBR |0 WBR * WBR * WBR * WBR 0 | WBR
WBR |0 WBR WBR 0 WBR * WBR * WBR * | WBRWBR
WBR |0 WBR WBR 0 WBR WBR 0 WBR * WBR * | WBR