求行列式元素

计算行列式计算一个四阶行列式：第

解： |a`````1`````0`````0| |-1````b`````1`````0| |0````-1`````c`````1| |0`````0````-1`````d| 上式=(r1+ar2)= |0````1+ab````a`````0| |-1`````b`````1`````0| |0`````-1`````c`````1| |0``````0````-1`````d| =[r1+(ab+1)r3]= |0```````0```c(ab+1)+a``ab+1| |-1``````b```````1`````````0| |0``````-1```````c````````...全部

  解： |a`````1`````0`````0| |-1````b`````1`````0| |0````-1`````c`````1| |0`````0````-1`````d| 上式=(r1+ar2)= |0````1+ab````a`````0| |-1`````b`````1`````0| |0`````-1`````c`````1| |0``````0````-1`````d| =[r1+(ab+1)r3]= |0```````0```c(ab+1)+a``ab+1| |-1``````b```````1`````````0| |0``````-1```````c`````````1| |0```````0``````-1`````````d| =[r1+(abc+a+c)r4]= |0```````0```````0```ab+1+d(abc+a+c)| |-1``````b```````1``````````0```````| |0``````-1```````c``````````1```````| |0```````0``````-1``````````d```````| =按(1,4)元展开, 得 abcd+ad+cd+ab+1。
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