中南大学matlab课后习题1.docx

第二章1·求下列表达式的值。（1）w=sqrt(2)*(1+0.34245*10^-6)w = 1.4142（2）a=3.5;b=5;c=-9.8;x=(2*pi*a+(c+b)/(pi+a*b*c)-exp(2))/(tan(b+c)+a);xx = 0.9829（3）a=3.32;b=-7.9;y=2*pi*a^2*[(1-pi/4)*b-(0.8333-pi/4)*a];yy = -128.4271（4）t=[2,1-3i;5,-0.65];z=1/2*exp(2*t)*log(t+sqrt(1+t^2));zz = 1.0e+004 * 0.0057 - 0.0007i 0.0049 - 0.0027i 1.9884 - 0.3696i 1.7706 - 1.0539i2，已知a，b，求下列表达式的值。a=[-1,5,-4;0,7,8;3,61,7];b=[8,3,-1;2,5,3;-3,2,0];（1）a+6*bans = 47 23 -10 12 37 26 -15 73 7a^2-b+eye(3)ans = -18 -217 17 22 533 109 21 867 526（2）a*bans = 14 14 16 -10 51 21 125 328 180a.*bans = -8 15 4 0 35 24 -9 122 0b*aans = -11 0 -15 7 228 53 3 -1 28（3）a/bans = 1.2234 -0.9255 2.9787 -0.9468 2.3511 -0.9574 4.6170 3.8723 13.8936b\aans = -0.5106 -8.6170 -1.1277 0.7340 17.5745 1.8085 -0.8830 -21.2128 0.4043（4）[a,b]ans = -1 5 -4 8 3 -1 0 7 8 2 5 3 3 61 7 -3 2 0[a([1,3],:);b^2]ans = -1 5 -4 3 61 7 73 37 1 17 37 13 -20 1 93.已知a，完成下列操作。a=[23,10,-0.778,0;41,-45,65,5;32,5,0,32;6,-9.54,54,3.14];输出a在[10,25]范围内的全部元素。k=find(a10a25)a(k)k =1ans = 23(2)取出a前3行构成矩阵b，前两列构成矩阵c，右下角3*2子矩阵构成矩阵d，b与c的乘积构成矩阵e。b=a(1:3,:)b = 23.0000 10.0000 -0.7780 0 41.0000 -45.0000 65.0000 5.0000 32.0000 5.0000 0 32.0000c=a(:,1:2)c = 23.0000 10.0000 41.0000 -45.0000 32.0000 5.0000 6.0000 -9.5400d=a(2:4,3:4)d = 65.0000 5.0000 0 32.0000 54.0000 3.1400e=b*ce = 1.0e+003 * 0.9141 -0.2239 1.2080 2.7123 1.1330 -0.2103(3)分别求表达式额ed,ed,e|d和~e|~d的值。edans = 0 1 0 0 0 1edans = 1 1 0 1 1 1e|dans = 1 1 1 1 1 1~e|~dans =0 0 1 0 0 04,产生5阶希尔伯特矩阵H和5阶帕斯卡矩阵P，且求其行列式的值Hh和Hp以及他们的条件数Th和Tp，判断哪个矩阵性能更好，为什