行列式d图提不上去,我就写,四阶,a1b1a1b2a1b3a1b4.a1b2行列式d图提不上去,我就写,四阶,a1b1a1b2a1b3a1b4.a1b2a2b2a2b3a2b4a1b3a2b3a3b3a3b4a1b4a2b4a3b4a4b4

Question

行列式d图提不上去,我就写,四阶,【】a1b1 a1b2 a1b3 a1b4.a1b2
行列式d图提不上去,我就写,四阶,【】a1b1 a1b2 a1b3 a1b4.a1b2 a2b2 a2b3 a2b4 a1b3 a2b3 a3b3 a3b4 a1b4 a2b4 a3b4 a4b4】

Answer 1

刚答了这个题目
第一列提出a1、第一列分别乘以-a2,-a3,-a4加到第二列、第三列、第四列.
D=a1*
b1 a1b2-a2b1 a1b3-a3b1 a1b4-a4b1
b2 0 a2b3-a3b2 a2b4-a4b2
b3 0 0 a3b4-a4b3
b4 0 0 0
= a1*(-1)^t(2341)*b4(a1b2-a2b1)(a2b3-a3b2)(a3b4-a4b3)
= -a1b4(a1b2-a2b1)(a2b3-a3b2)(a3b4-a4b3).