大学线性代数讲义前面有对知识的讲解,后面是习题。便于理解。不想挂科的同学们的必备之物

~µA S §| x1+2x2+3x3=07x1 x2+6x3=0

2x1+2x2+x3=0

123 123

A:D= 7 16 = 0 15 15 =0.ÏdT §| k0A.

221 0 2 5

x1+2x2+3x3 2x4=6 2x x 2x 3x=81234

~µA §|

3x1+2x2 x3+2x4=4

2x1 3x2+2x3+x4= 8

123 2 3 2 12

2 1 2 3 2 1 2 3

== AµXêI ªD=

13 32 12 15

2 320 244 1

123 2 123 2 123 2

01 27 00 1815 0 5 81

=18×18. = =

00 1815 01 27 01 27

0 2400018 000184

64 4 4 4 23 2 20 20

0 1 1813 8 1 2 3 8 1 2 3

D1= = =

00 4536 02 910 42 12

8 32 00 1818 0 40 21

163 2

28 2 3

= 2(18)( 45+36)= 2(18)( 9)=182.D2= =

34 12

2 821

12 6 2 36 12 2 18 3 2 1 28

36×18.D3= = 182.D4= =

32 42 32 14 2 3 81 2 32 8

36×18.Ïd,x1=D1/D=1,x2=D2/D=2,x3=D3/D= 1,x4=D4/D= 2.