求用matlab 解方程组的方法.
来源:百度知道 编辑:UC知道 时间:2024/05/21 11:08:47
2X1-2X2+X4+3=0
2X1+3X2+X3-3X4+6=0
3X1+4X2-X3+2X4=0
X1+3X2+X3-2=0
2X1+3X2+X3-3X4+6=0
3X1+4X2-X3+2X4=0
X1+3X2+X3-2=0
A=[2 -2 0 1;2 3 1 -3;3 4 -1 2;1 3 1 0]
B=[-3;-6;0;2]
X=A\B
%或
X=inv(A)*B
%验算
b=A*X
结果:
A =
2 -2 0 1
2 3 1 -3
3 4 -1 2
1 3 1 0
B =
-3
-6
0
2
X =
-1.8052
0.7273
1.6234
2.0649
X =
-1.8052
0.7273
1.6234
2.0649
b =
-3.0000
-6.0000
0.0000
2.0000
用矩阵写,就是
[2 -2 0 1
2 3 1 -3
3 4 -1 2
1 3 1 0]×[x1 x2 x3 x4]'=[-3 -6 0 2]'
记为A×[x1 x2 x3 x4]'=C
则
[x1 x2 x3 x4]'=inv(A)*C
ans =
-1.8052
0.7273
1.6234
2.0649