matlab课后习题及答案以供大家学习及参考
y =
-0.9880 0.8509 -0.3048 >> y=cos(x) y =
0.1543 0.5253 -0.9524
>> y=tan(x)
y =
-6.4053 1.6198 0.3200
>> cot(x) ans =
-0.1561 0.6174 3.1246
7.矩阵a为[1 2 3; 4 5 6; 7 8 9],求a的LU分解。
>> a=[1 2 3; 4 5 6; 7 8 9]; >> [l,u]=lu(a) l =
0.1429 1.0000 0 0.5714 0.5000 1.0000 1.0000 0 0 u =
7.0000 8.0000 9.0000 0 0.8571 1.7143
0 0 0.0000
8.矩阵a为[1 1 1 1;1 2 3 4;1 3 6 10;1 4 10 20]，求a的Cholesky分解和QR分解。 >> a=[1 1 1 1;1 2 3 4;1 3 6 10;1 4 10 20]; >> [u s v]=svd(a) u =
-0.0602 -0.5304 0.7873 -0.3087 -0.2012 -0.6403 -0.1632 0.7231 -0.4581 -0.3918 -0.5321 -0.5946 -0.8638 0.3939 0.2654 0.1684 s =
26.3047 0 0 0 0 2.2034 0 0 0 0 0.4538 0 0 0 0 0.0380 v =
-0.0602 -0.5304 0.7873 -0.3087 -0.2012 -0.6403 -0.1632 0.7231 -0.4581 -0.3918 -0.5321 -0.5946 -0.8638 0.3939 0.2654 0.1684 >> [q,r]=qr(a) q =
-0.5000 0.6708 0.5000 0.2236 -0.5000 0.2236 -0.5000 -0.6708 -0.5000 -0.2236 -0.5000 0.6708 -0.5000 -0.6708 0.5000 -0.2236