2 - 2r1
X-1 0 -2
2-2X X-1 0
-(a+5) a+2 X-2a
c1 + 2c2
X-1 0 -2
0 X-1 0
a-1 a+2 X-2a
按第2行展开 D = (X-1) *
X-1 -2
a-1 X-2a
= (X-1) ( X^2 - (2a+1)X + 2(a-1) )
= (X-1) ( X^2 - (2a+1)X + 2(2a-1) )
= (X-1) (X-2)(X-2a+1)
特征值为 1,2,2a-1
2 - 2r1
X-1 0 -2
2-2X X-1 0
-(a+5) a+2 X-2a
c1 + 2c2
X-1 0 -2
0 X-1 0
a-1 a+2 X-2a
按第2行展开 D = (X-1) *
X-1 -2
a-1 X-2a
= (X-1) ( X^2 - (2a+1)X + 2(a-1) )
= (X-1) ( X^2 - (2a+1)X + 2(2a-1) )
= (X-1) (X-2)(X-2a+1)
特征值为 1,2,2a-1