(0 )2 1436587@9BAC9EDGF4HI 7P5QHRFTSVU0DXW6F4H

¤£ ¡ 1
det M =
m
1 1
m
= m
1
1
m −
1 m 1
1 1 m
1 1
1 m
= m (m 2 − 1) − (m − 1) + 1 − m
= m (m − 1) (m + 1) − 2 (m − 1)
= (m − 1) (m (m + 1) − 2)
= (m − 1) (m 2 + m − 2)
= (m − 1) 2 (m + 2)
+
1 m
1 1
M
¡ ¨ det M = 0 ¡ m = 1 m = −2
¨ ¡
¤
M −1 = 1
det M
=
M =
m−1
(m−1) 2
m + 1 −1 −1
−1 m + 1 −1
(m+2)
−1 −1 m + 1
m + 1 −1 −1
1
−1 m + 1 −1
(m−1)(m+2)
−1 −1 m + 1
¡ ¨ §§ A n ¨
A
¡ ¨
¤
( A) −1 = 1
|A| A = (A −1 )
A| = n−1
|A|
|
n−2
A) = |A|
A
(
¡ ¨ A A A = In£¢ |A|
|A| = 0 A = |A| InA−1 = |A| A−1 ¨ ¨
¡
¨¥ ¨
¡
−1 −1
A) = ( |A| A = 1
−1
A |A|
−1 1
= |A| A
A −1
A −1 = |A −1 | In = 1
|A| In
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