澳洲IT编程assignment代写 计算机代写
5.  X(end)
7. size (X)
10. They are linearly dependent
11. length (u)
12.
12-a)
u'     % u transpose
12-b)
u * v  % ERROR: u and v are both column vectors
12-e)
u .* v % element by element multiplication
13. sum(X) % summation of each column vector of X
14. Read help for function 'sum'
 澳洲IT编程assignment代写 计算机代写
sum(X') 
sum(X,1) % summation of first dimmension, row vector
sum(X,2) % summation of second dimmension, column vector
15. mean(X) % mean of each column vector
16. log(X)  % logarithm of each element of X
17. abs(X)  % absolute value of each element of X
19. X(:,2) + v'
20. [1 1] * X % summation of each column of X
22. From the table we can construct a matrix (vitamin contents in different food types, observe the link between traditional methods and matrix methods.
C = [0.5 0.5 0 0; 0.3 0 0.2 0.1; 0.1 0.1 0.2 0.5];
Consumption of each food, a vector q = [5 10 8];
Answer for the first question: q * C
Prices for each vitamin: p = [10 20 25 50];
Answer for the second question: p * C'
23. Similar to 22
Resources matrix of each style
R = [5 20 16 7 17; 7 18 12 9 21; 6 25 8 5 13];
Orders
v = [5 7 12]
Answer to the first question: v * R
Costs matrix for purchase and transportation: C = [15 4.5; 8 2; 5 3; 1 0.5; 10 0];
% Answer to the second question: Quantities * Costs
24. D^k becomes a zero matrix if k goes to infinity
25. the power of a diagonal matrix is a diagonal matrix composed by the power of it's diagonal elements
26. [u v] % horizontal concatenation, u and v must have same number of rows
27. U = diag(u) elements of vector u become the diagonal elements of matrix U
28. Read the help for function diag
diag(u, -1): puts elements of u on the first diagonal above the main diagonal
diag(u, 1): puts elements of u on the first diagonal below the main diagonal
29.  
a) [x₂ x₃ x₄ 0]
b) [x₃ x₄ 0 0]
c) [x₄ 0 0 0]
d) [0 0 0 0]
e) [-1 -1 -1 x₄]
30.
a) [x₁+x₂+x₃+x₄    x₂+x₃+x₄     x₃+x₄     x₄]
b) [x₁+2x₂+3x₃+4x₄    x₂+2x₃+3x₄     x₃+2x₄     x₄]
c) [x₁+3x₂+6x₃+10x₄    x₂+3x₃+6x₄     x₃+3x₄     x₄]