How to express the assignment to a vector after the multiplication of 2 × 2 matrix and two-dimensional vector in MATLAB?

How to express the assignment to a vector after the multiplication of 2 × 2 matrix and two-dimensional vector in MATLAB?

A = rand (2)% 2 is a random vector
B = rand (2,2)% second order random matrix
c=a*b
That will do

How does matlab transform line vector into matrix vector?
a=[1,2,3,4,5,6,7.9]
How to turn a into a matrix
b=[123;
456;789]?

reshape(a,3,3)'
ans =
1 2 3
4 5 6
7 8 9

The problem of vector multiplication in MATLAB
It is known that t = 0:1:20;
A=[1,0,0;0,1,0;0,0,1];
B=[-sin(t),cos(t),sin(t);-t,t,tan(t);sin(t),cos(t),cos(t)];
C=[1,0,1;0,1,0;0,0,1];
How to find a * b * C

If t is a vector, the dimension of B is 3 * 63, which does not satisfy the multiplication of matrix, so t is a scalar. Direct calculation shows that a is the identity matrix, a * b = Ba * b * C = b * C = [- sin (T), cos (t), 0; - t + Tan (T), t, Tan (T); sin (T) + cos (T), cos (T), cos (T)]; direct multiplication is good with MATLAB, for t = 0:1:2

When can two matrices be multiplied to exchange positions

A. B is commutative if and only if a can be expressed as a polynomial of B. This can be proved by Jordan canonical form
Please refer to "linear algebra and matrix theory" 243-244

What is the transpose matrix of the identity matrix

I'm very skeptical that you're asking about orthogonal matrices
Unit matrix transpose or unit matrix
Transpose of orthogonal matrix is its inverse

What can be written as the transpose of the addition of two matrices and the transpose of the multiplication of two matrices? For example, (a * b) '=?, (a + b)' =?

(a + b) transpose = a transpose + B transpose, (AB) transpose = B transpose * a transpose

If multiplication of two matrices equals zero, is transpose of one matrix multiplied by the other also equal to zero?

Your conclusion is not tenable, and the figure is a counterexample. In addition, please put your questions in the mathematical classification. The economic mathematics team will help you answer them, please evaluate them in time

How to calculate the inverse matrix of the second order matrix? For example, 0, 2, 20

Thank you for your reminding
A times a * = | a | e
A^-1= A*/|A|
Here | a | = - 4
Finding adjoint matrix A of second order matrix*
It can directly exchange the position of the main diagonal of a and the change of the sign
obtain
0 -2
-2 0
So a ^ - 1 = a * / | a | = 0 1 / 2
1/2 0

Finding the inverse of a fourth order matrix
 

(A,E) =1 3 -5 7 1 0 0 00 1 2 3 0 1 0 00 0 1 2 0 0 1 00 0 0 1 0 0 0 1r1-7r4,r2-3r4,r3-2r41 3 -5 0 1 0 0 -70 1 2 0 0 1 0 -30 0 1 0 0 0 1 -20 0 0 1 0 0 0 1r1+5r3,r2-2r31 3 0 0 1 0 5 -170 1 0 0 0 1 -2 10 ...

How to find the inverse matrix of fourth order determinant

A = 4 × 4 matrix e = 4 × 4 unit matrix
By constructing an augmented matrix [a | e] and making elementary row transformation, [e | A-1] is obtained
Another formulation is a form of calculation, to get a certain value and matrix is not the same meaning, please note