MATLAB实验二-矩阵基本运算(一)答案.docVIP

MATLAB实验二-矩阵基本运算(一)答案

ans=

0.50001.00004.0000

1.33330.20002.5000

0.60001.50000.7778

ans=

2.00001.00000.2500

0.75005.00000.4000

1.66670.66671.2857

A/B和B\A的值是否相等？

A=[234;415;367];

B=[431;352;549];

A/B,

B/A

ans=

-0.34520.51190.3690

0.7857-0.78570.6429

-0.97621.30950.5952

ans=

110.0000-15.0000-52.0000

92.0000-13.0000-43.0000

-22.00004.000011.0000

A/B和B\A所代表的数学含义是什么？

解：A/B是B*A的逆矩阵B\A是B*A的逆矩阵

（2）写出完成下列操作的命令。

1）将矩阵A第2—5行中第1，3，5列元素赋给矩阵B。

A=[0.95010.45650.92180.41030.13890.0153

0.23110.01850.73820.89360.20280.7468

0.60680.82140.17630.05790.19870.4451

0.48600.44470.40570.35290.60380.9318

0.89130.61540.93550.81320.27220.4660

0.76210.79190.91690.00990.19880.4186]

B=A(2:5,[1,3,5])

A=0.95010.45650.92180.41030.13890.0153

0.23110.01850.73820.89360.20280.7468

0.60680.82140.17630.05790.19870.4451

0.48600.44470.40570.35290.60380.9318

0.89130.61540.93550.81320.27220.4660

0.76210.79190.91690.00990.19880.4186

B=0.23110.73820.2028

0.60680.17630.1987

0.48600.40570.6038

0.89130.93550.2722

2）删除矩阵A的第7号元素。

A=rand(6,6);

A(7)=[inf]

A=

0.8385Inf0.17300.13650.28440.5155

0.56810.62130.97970.01180.46920.3340

0.37040.79480.27140.89390.06480.4329

0.70270.95680.25230.19910.98830.2259

0.54660.52260.87570.29870.58280.5798

0.44490.88010.73730.66140.42350.7604

3）将矩阵A的每个元素值加30。

B=A+30

B=

30.950130.456530.921830.410330.138930.0153

30.231130.018530.738230.8936