![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
Let a be a third-order matrix, a be partitioned by column as a = (α 1, α 2, α 3), and matrix B = (α 3,3, α 1-2, α 3, α 2 + α 3). If | a | = - 2, find | B | I, the answer is 6, but the answer is - 6, and find analysis
Block matrix is a problem,
A. If B is a square matrix of order m and N, a = a, B = B, C = the first row 0 a, and the second row b 0, then C =? The answer is (- 1) ^ Mn * ab. the question is why is the sign determined by Mn?
(- 1) ^ Mn is - 1 only when m and N are both odd numbers. For example, a = [1 1; 1 1] B = [1] C = 0 1 10 1 1 100 expand by the first column is C = 0 + 0 + 1 * A. when a = [1] B = [1], C = 0 11 0 expand by the second column, C = 0 + (- 1) a can be understood as the symbol has a certain relationship with Mn
1、 The second order matrix A = {2, - 1} - 1,2 is used to find the nth power matrix of A. 2. The third order matrix A is divided into (A1, A2, A3) by column, and | a | = 5
1、 Matrix A of order 2 = {2, - 1}
-1,2 find the nth power matrix of A
2、 If the third-order square matrix A is partitioned into (A1, A2, A3) and | a | = 5, B = (a1 + 2a2.3a1 + 4a3,5a2), then | B | =?
If the vector a (2,1) is rotated 45 ° counterclockwise around the origin to get the vector B, what is the coordinate of B,
If the vector a (2,1) is rotated 45 ° anticlockwise around the origin to get the vector B, then the coordinates of B are better to have a graph
Using the method of solving triangle: in the process of rotation, the length of hypotenuse does not change, or the root sign is 5
Let the original angle be α, then cos α = 2 / radical 5
Sin α = 1 / radical 5
After 45 ° rotation, cos (α + 45 °) = (radical 10) / 10
The abscissa of point B is [(radical 2) / 2] and the ordinate is [1.5 times (radical 2)]
It is known that P is a moving point on the parabola y = 1 / 2x & #. The projection of point P on the x-axis is m, and the coordinates of point a are (6,17 / 2), then the minimum value of PA + PM is?
If y = x & # 178 / 2, focus f (0,0.5), collimator y = - 0.5, extend PM collimator to H point, then PA = pH
∴PM=PH-0.5=PF-0.5
We can only find the minimum value of PF + PA
From the fact that both sides of the triangle are longer than the third side, PF + PA > = fa (straight line segment), (formula 1)
Let the straight line FA and the parabola intersect at point P 0, then p 0 (3,4.5) can be calculated, and the other intersection (- 1 / 3,1 / 18) can be rounded off
When p coincides with P0, (formula 1) can get the minimum value, and FA = 10
Then PM + PA = 19 / 2
(1 + e ^ x) ^ - 0.5 indefinite integral
For a barrel of oil, the total mass of the oil and the barrel is 9.5kg. If you know that the mass of the oil minus the mass of the barrel is 8.5Kg, you can calculate the mass of the oil and the barrel respectively?
9.5-8.5 = 1kg
Oil 1 / 2 = 0.5kg
Barrel 9.5-0.5 = 9kg
The relationship between area and perimeter of parallelogram
Area = AB perimeter = (a + b) 2
Now there are 36 chickens and rabbits, each chicken has 2 legs and each rabbit has 4 legs. Now the dish has 80 legs. How many chickens and rabbits are there?
Now there are 36 chickens and rabbits, each with 2 legs and each with 4 legs. Now there are 80 legs. How many chickens are there? How many rabbits are there? We need four operations, not equation solutions,
Suppose there are x chickens, and each chicken has 2 legs, X chickens have 2x legs;
Because suppose there are x chickens and 36 rabbits, that is, there are 36-x rabbits and each rabbit has 4 legs, then 36-x rabbits have 4 * (36-x) legs;
At present, there are 80 legs, that is, 2x + 4 * (36-x) = 80,
Calculation: 2x + 4 * 36-4 * x = 80, get x = 32 chickens, then rabbits: 36-32 = 4
Vertex a (4,0), B (6,7), C (0,3) of known triangle ABC
Find: (1) the linear equation of AC edge, and turn it into general equation. (2) the linear equation of AC edge, and turn it into general equation
(1)Y=-3/4X+3
(2)K=4/3
Replace the coordinates of B
Y=4/3X-1
RELATED INFORMATIONS
- 1. A simple matrix exercise, Matrix a [1,0] m matrix [a, b], a and M matrix are interchangeable, determine the relationship between a, B, C, D, and write matrix M [ 2,-1] [ c,d] In addition, I want to ask the next matrix 2 * 3, will it have the reciprocal of the matrix
- 2. Please look at the problem about matrix for me Let the fourth-order matrix A = (x, - R2, R3, - R4) B = (y, R2, - R3, R4), where x, y, R2, R3, R4 are all four-dimensional column vectors, and the determinant IAI = 4, IBI = 1, then the determinant ia-bi =? I I is the determinant of a matrix
- 3. Please explain the meaning of the following sentence and give a specific example: elementary row transformation is equivalent to multiplying a matrix left by an invertible matrix
- 4. The problem of finding adjoint matrix The form of adjoint matrix is A11 A21 A31 A12 A22 A32 A13 A23 A33 Why not A11 A12 A13 A21 A22 A23 A31 A32 A33 In addition, if the transpose of determinant is equal to the original determinant, what is the relationship between the transpose of matrix and the original matrix?
- 5. Find the similarity transformation matrix P such that | 1,2,2 2,1,2 2,2,1| Reduced to diagonal matrix
- 6. Use the formula method to solve the inverse matrix of the following matrix A, A = 1 4 0 5 2 1 2 3 3
- 7. How to solve the matrix [34 - 641241 - 12 - 70] and change the matrix into ladder matrix and simplest matrix
- 8. (2-1-11; 11-21; 36-97) is reduced to the simplest form matrix
- 9. How to merge matrix A = [0,1,2], matrix B = [5,6,7] into matrix C = [0,5,1,6,2,7]
- 10. How to calculate matrix division in MATLAB?
- 11. A matrix exercise 1. Known matrix A= 1 -1 1 2 4 x -3 -3 5 And B= 2 0 0 0 2 0 0 0 Y Where p ^ - 1AP = b Find x, y, matrix P
- 12. A matrix problem! 1 4 2 A= 0 -3 -2 0.43 to the nth power of A
- 13. How to find the modular formula of matrix
- 14. Is there any formula for matrix (AB)^T= (A+B)^T= (AB)^-1= (A+B)^-1= (AB)*= (A+B)*=
- 15. What is the multiplication formula of second order matrix
- 16. Let a be a matrix of order n, satisfying AA ^ t = e (E is the identity matrix of order n), a ^ t be the transpose matrix of a, and | a|
- 17. Let a be a square matrix of order n, satisfying AA ^ t = e (E is the identity matrix of order n), | a|
- 18. Let a be a square matrix of order n and a * be the adjoint matrix of A. It is proved that N, R (a) = n, R (a *) = 1, R (a) = N-10, R (a)
- 19. Let the adjoint matrix of matrix A of order n be a *, and prove that: (1) if | a | = 0, then | a * | = 0 What is rank? I haven't learned it, and I can't understand it I can't understand what I've done with the counter evidence If you use the method of disprovement to write down clearly
- 20. The matrix with the same eigenvalue of linear algebra and matrix A is the adjoint of transpose a of inverse matrix A of a * a, which one? Why?