用初等变换法求逆矩阵~

(A,E)=1 1 1 1 1 0 0 01 1 -1 -1 0 1 0 01 -1 1 -1 0 0 1 01 -1 -1 1 0 0 0 1第1行乘-1加到2,3,4行1 1 1 1 1 0 0 0 0 0 -2 -2 -1 1 0 0 0 -2 0 -2 -1 0 1 0 0 -2 -2 0 -1 0 0 1 r3-r2-r31 1 1 1 1 0 0 0 0 0 -2 -2 -1 1 0 0 0 -2 0 -2 -1 0 1 0 0 0 0 4 1 -1 -1 1 r2*(-1/2),r3*(-1/2),r4*(1/4),r2r31 1 1 1 1 0 0 0 0 1 0 1 1/2 0 -1/2 0 0 0 1 1 1/2 -1/2 0 0 0 0 0 1 1/4 -1/4 -1/4 1/4 r1-r4,r2-r4,r3-r41 1 1 0 3/4 1/4 1/4 -1/40 1 0 0 1/4 1/4 -1/4 -1/40 0 1 0 1/4 -1/4 1/4 -1/4 0 0 0 1 1/4 -1/4 -1/4 1/4 r1-r2-r31 0 0 0 1/4 1/4 1/4 1/40 1 0 0 1/4 1/4 -1/4 -1/40 0 1 0 1/4 -1/4 1/4 -1/4 0 0 0 1 1/4 -1/4 -1/4 1/4 逆就是右边那个4*4块