问题2.1如何将A的2,3列互换？>>A=[3,5,6;,2,5,8;3,5,9;3,7,9]A=356258359379>>A(:,[1,3,2])ans=365285395397>>t1=A(:,2);t2=A(:,3);>>A(:,3)=t1;A(:,2)=t2A=3652853953971．输入一个矩阵A，取出A的第2行第1列的元素；取出A的第1，3，4列的所有元素；让A的第1列和第3列互换；删除A的第二列。>>A=[3,5,6,1;,2,5,8,4;3,5,9,3;3,7,9,6]A=3561258435933796>>A(2,1)ans=2>>A(:,[1,3,4])ans=361284393396>>A(:,[3,2,1,4])ans=6531852495339736>>A(:,[2])=[]A=3612843933962．用MATLAB可以识别的格式输入下面两个矩阵。再求出它们的乘积矩阵C，并将C矩阵的右下角2×3子矩阵赋给D矩阵，赋值完成之后，调用相应的命令，查看MATLAB工作空间的情况。>>A=[1233;2357;1357;3239;1894]A=12332357135732391894>>B=[1+4i43678;233554+2i;26+7i5342;189543]B=1.0000+4.0000i4.00003.00006.00007.00008.00002.00003.00003.00005.00005.00004.0000+2.0000i2.00006.0000+7.0000i5.00003.00004.00002.00001.00008.00009.00005.00004.00003.0000SC=1.0e+002*0.1400+0.0400i0.5200+0.2100i0.51000.40000.41000.3100+0.0400i0.2500+0.0800i1.0300+0.3500i1.03000.77000.77000.5900+0.0600i0.2400+0.0400i0.9900+0.3500i1.00000.71000.70000.5100+0.0600i0.2200+0.1200i1.0800+0.2100i1.11000.82000.79000.6500+0.0400i0.3900+0.0400i1.1400+0.6300i1.08000.93000.99000.7000+0.1600iD=C(4:5,4:6)D=82.000079.000065.0000+4.0000i93.000099.000070.0000+16.0000i3.已知，B=，求i）A*B-2Aii）A*Biii）A.*Biv）A*B-B*AA=[1,1,1;-1,1,1;1,-11]A=111-1111-11>>B=[121;13-1;214]B=12113-1214>>A*B-2*Aans=242400024A*Bans=464222206A.*Bans=121-13-12-14>>A*B-B*Aans=4405-3-1-31-12．将A的第2行元素扩大2倍后作为A的第3行元素。>>A=rand(3,4)A=0.69460.95680.17300.25230.62130.52260.97970.87570.79480.88010.27140.7373>>B=2*A(2,1:4)B=1.24261.04521.95951.7515>>A(3,1:4)=BA=0.69460.95680.17300.25230.62130.52260.97970.87571.24261.04521.95951.75153．输入任意矩阵A、B（它们的元素个数相等），命令A(:)和A(:)=B会产生什么结果？A(:)是把矩阵按存储顺序进行列排，成为1列的矩阵。A(:)=B是把B矩阵的元素按存储顺序替换为A的元素，且A的行数列数不变。柱状图的标注x=[213387220280280180];explode=[100000];pie(x,explode,{'¼ÆËã»úϵ','ÍâÓïϵ','ÒôÀÖϵ','ÃÀÊõϵ','ÖÐÎÄϵ','Àí¿Æϵ'});饼状图的标注x=[213387220280280180];bar(x);figure(1)h=gca;get