57 articles trouvés pour ce sujet.
|
|
|
|
|
|
|
|
Matrice |
2006-02-01 |
|
Kader pose la question : mon probleme est le suivant soit deux matrices carrees A et B d'ordre n qui sont anticommutatives AB= -BA , demontrer que au moins une des deux matrices n'est pas inversible si n est impair.
je n'arrive pas a utiliser le fait que n soit impair, trouver le rapport entre n impair et inverse des matrices, je pars sur la base de DETAB=DETA*DETB Claude Tardif lui répond. |
|
|
|
|
|
4 games in 4 time slots with 8 teams |
2015-10-16 |
|
Paul pose la question : I'm trying to set up a game matrix for my kids that will have 4 games in 4 time slots with 8 teams. And every team is playing a different game in a different time slot. I provided the initial matrix and I am trying to ensure that no 2 teams play each other more than once. That's my problem.
8 pm 9 pm 10 pm 11 pm
Crokinole 1 vs 2
Trivial Pursuit 3 vs 4
Darts 5 vs 6
Pictionary 7 vs 8
Please help, I've been at it for hours. Robert Dawson and Victoria West lui répond. |
|
|
|
|
|
Matrices |
2013-11-10 |
|
Ricky pose la question : Why must we have brackets around matrices. Why don't we just neatly write an array of entries cross-wise and up and down to indicate a particular matrix? Chris Fisher lui répond. |
|
|
|
|
|
Row echelon form |
2013-03-15 |
|
Shawn pose la question : Please help me put matrix in row echelon form:
1 9 8 0
5 8 1 35
1 -4 -1 17 Penny Nom lui répond. |
|
|
|
|
|
The (i, j) entry of a matrix |
2012-02-17 |
|
Bilyaminu pose la question : Question Bilyaminu
Find a formula for the (i,j) entry of a matrices: A= [1 2 3 4; 5 6 7 8; 9 10 11 12; 13 14 15 16] Harley Weston lui répond. |
|
|
|
|
|
Augmented matrix |
2011-12-14 |
|
Britney pose la question : Write Augmented matrix and use row reduction to solve.
I need major help with this problem! Tomorrow is my semester test and I have no idea how to do this.
2x+5y=8
y-x=10 Robert Dawson lui répond. |
|
|
|
|
|
Geocaching |
2010-10-15 |
|
Clint pose la question : I am stuck on a puzzle for Geocaching which is a GPS game.
I know it is a number matrix but don't know how to start.
[1 -7 16 -3 -9; 1 -3 18 -20 -33] x [1 8 -9 3 5; 0 1 0 4 2; 0 0 1 2 1; 0 0 0 1 -1; 0 0 0 0 1] = ? Stephen La Rocque lui répond. |
|
|
|
|
|
Reflection in the line y = x |
2010-07-21 |
|
tousif pose la question : Find the 2 x 2 matrix which represents a reflection in the line y = x?
Please help.... Penny Nom lui répond. |
|
|
|
|
|
The adjacency matrix of an undirected graph |
2010-01-15 |
|
Bhavya pose la question : Let Cn be the undirected graph with vertex set V = {1,2,3,...,n} and edge set E = {(1,2), (2,3), (3,4),.... , (n-1,n), (n,1)}. Let An be the adjacency matrix of Cn.
a. Find the determinant of An.
b. Find (An)^2 Robert Dawson lui répond. |
|
|
|
|
|
Elements of a Matrix |
2009-12-28 |
|
peter pose la question : I have a array of 10 by 6 I would like to know how to find the terms 11 12 and tell me de formula the array is:
23 03 01 05 03 08 02 06 03 06
24 04 08 09 04 25 13 15 05 08
26 09 19 12 06 31 22 29 16 21
31 10 24 22 15 32 34 33 27 24
32 32 25 33 30 34 35 34 31 35 Janice Cotcher lui répond. |
|
|
|
|
|
Proof of a Unique Solution |
2009-07-24 |
|
muele pose la question : Find matrix A such that A is not invertible, and
b such that Ax=b has a unique solution Robert J. Dawson lui répond. |
|
|
|
|
|
Finding an Array to an Integer Linear Programming Problem |
2009-05-12 |
|
Debbie pose la question : how to make an array for 3 box of juice for 25 students and 2 teacher. 1 pack of juices
hols 3boxes the answer is 9 packages but how do you make array for this Janice Cotcher lui répond. |
|
|
|
|
|
A linear system |
2009-03-13 |
|
Rasanga pose la question : Use the row echelon form of the augmented matrix to solve the following linear system.
X1+2X2+X4=6
X3+6X4=7
X5=1 Harley Weston lui répond. |
|
|
|
|
|
Augmented matrix: independent, dependent, or inconsistent? |
2009-02-23 |
|
Anna pose la question : Perform row operations on the augmented matrix as far as necessary to determine whether the system is independent, dependent, or inconsistent.
x + y + z = 11
x - y + 3z = 5
2x + 2y + 2z = 15 Harley Weston lui répond. |
|
|
|
|
|
The column space of a matrix |
2009-02-12 |
|
John pose la question : Question from John, a student:
A=
1 1 0 0
1 1 0 0
0 0 1 0
0 0 1 1
B=
1 5 6
1 5 6
0 7 2
0 0 9
Is the space spanned by the columns of A the same as the space spanned by the columns of B? Harley Weston lui répond. |
|
|
|
|
|
Using the augmented matrix |
2008-10-17 |
|
Karlena pose la question : I am supposed to write the augmented matrix of the system and use the matrix method to solve the system. I must show my work algebraically
x+y+2z=30
2x+3y+2z=53
x+2y+3z=47 Harley Weston lui répond. |
|
|
|
|
|
A linear system |
2008-08-23 |
|
dipesh pose la question : consider the system of equations
x-6y+2z=5
2x-9y-z=14
4x+12y-3z=19 by reducing the augm matrix to row echelon form, find
the solution to the equation.
leaving the first two equations the third is changed to -3x+6y+14z=-31
show the equations have infinitely many solutions and give a general
formula for them Penny Nom lui répond. |
|
|
|
|
|
solving four simultaneous equations |
2008-07-18 |
|
Muhammad pose la question : -2B-2C+4E=1
A+B+C+D=0
-2B-2C-2D+E=0
B+C+4D-2E=0 Janice Cotcher lui répond. |
|
|
|
|
|
Determinants |
2008-05-02 |
|
Henry pose la question : I have a question about solving 3x3 matrices.
The traditional way, or at least the way I've been taught, is that if one has a 3x3 matrix such as:
[ a b c ]
[ d e f ]
[ g h i ]
one solves it according to this formula:
[ei - hf) - (bi - hc) + (bf - ec) = determinant.
According to a book I'm now studying to prepare for the California CSET exam, there is another, easier, way to solve it:
[ a b c ] [ a b ]
[ d e f ] [ d e ]
[ g h i ] [ g h ]
In other words, one repeats the first two rows of the matrix and adds them to the right.
At this point, the determinant is calculated thus:
(aei) +(bfg) + (cdh) - (gec) - (hfa) - (idb).
Is this, in fact, correct? Harley Weston lui répond. |
|
|
|
|
|
Matrix multiplication |
2008-04-08 |
|
manashi pose la question : i. why matrix division is not possible?
ii.when we add or subtract two matrix , getting the result by addind or subtracting correspondind elements....but in case of multiplication it is not but why? Harley Weston lui répond. |
|
|
|
|
|
Row echelon form |
2008-02-21 |
|
cOCO pose la question : USE ELEMENTARY ROW OPERATIONS TO WRITE THE MATRIX BELOW IN ROW
ECHELON FORM.
1 1 8 - 2
2 -1 1 11
2 1 14 -11 Penny Nom lui répond. |
|
|
|
|
|
Animals for sale |
2007-12-09 |
|
Marion pose la question : This question has come up and I know the answer and the equation, but how do you solve this?
Please share the proof. cows=$10, pigs=$3, chickens=$.50
In any combination buy 100 animals with $100. Leeanne Boehm lui répond. |
|
|
|
|
|
An augmented matrix |
2007-11-29 |
|
Beth pose la question : I am having troubles fiinding this augnmented matrix. I know how to do it
but everytime i do it it get a different answer and its not the right answer.
Could you help me to make sure I do it right?
Here is the problem:
4x - 3y = 5
2x +9y = 6 Harley Weston lui répond. |
|
|
|
|
|
Area of a 17-sided lot |
2007-11-21 |
|
Lynda pose la question : My uncle is wanting to buy this piece of land [a 17-sided polygon] but we are questioning the acerage total. the measurements are [on the attached diagram]. Stephen La Rocque lui répond. |
|
|
|
|
|
A matrix equation |
2007-11-16 |
|
stephanie pose la question : Im supposed to solve
( 1 tan =E8/2) ( 1 tan =E8/2)^(-1)
(-tan =E8/2 1 ) (-tan =E8/2 1 )
Matrix AA<(-1)=I Penny Nom lui répond. |
|
|
|
|
|
Linear systems and inverses |
2007-08-06 |
|
Marsia pose la question : explain how inverses are used to solve linear systems. Penny Nom lui répond. |
|
|
|
|
|
A matrix of polynomials |
2007-07-18 |
|
Mac pose la question : can you please help me out to solve this ?
Let A be a n*n matrix, the elements of which are real (or complex) polynomial in x.
If r rows of the determinant becomes identical when x=a, then the determinant
A) has a factor of order r
B) has a factor or order > r
C) has no factor
D) has a factor of order < r Harley Weston lui répond. |
|
|
|
|
|
An augmented matrix |
2007-02-13 |
|
Mary pose la question : I've been trying for quite some time now to figure this out. I have to solve this by using the Gauss-Jordan Method: 3x - y = 15 2x + 3y = 10 Can anyone help me? Penny Nom and Gabriel Potter lui répond. |
|
|
|
|
|
Nickels, dimes and quarters |
2007-02-05 |
|
Avinash pose la question : Mary has 48 coins made up of nickels, dimes and quarters with a total value of $5.10. She has 4 more dimes than nickels and quarters combined. How many coins of each kind does she have? Use matrix to solve the system Stephen La Rocque lui répond. |
|
|
|
|
|
Induction |
2006-10-31 |
|
Ross pose la question : Suppose that A and B are square matrices with the property AB= BA. Show that AB^n = B^n A for every positive integer n. Stephen La Rocque and Penny Nom lui répond. |
|
|
|
|
|
A matrix equation |
2006-10-14 |
|
Ngozi pose la question : If I have AB = C, where A and C are both 1x6 matrixes and B is a 6x6 matrix, how can I solve for B by dividing C over A? Chris Fisher lui répond. |
|
|
|
|
|
Who is taller: John or Mary? |
2005-09-14 |
|
Ulises pose la question : All the students in a school are arranged in a rectangular array. After that, the tallest student in each row was chosen, and then among these John Smith happened to be the shortest.Then, in each column, the shortest student was chosen, and Mary Brown was the tallest of these. Who is taller: John or Mary? Penny Nom and Claude Tardif lui répond. |
|
|
|
|
|
A matrix problem |
2005-04-04 |
|
Alan pose la question :
Let A = |
|
1 | -1 | 0 |
|
2 | -1 | 2 |
a | b | c |
where a, b, c are constant real numbers. For what values of a, b, c is A invertible? [Hint: Your answer should be an equation in a, b, c which satisfied if and only if A is invertible.]
Judi McDonald lui répond. |
|
|
|
|
|
Two matrix problems |
2005-03-30 |
|
Sue pose la question : Question 1
Suppose all matrices in the equation below are square and invertible. Solve for x .
BA-1XB-1 + 2BA + In = 0 (the symbol "0" here denotes the matrix of all 0's in it)
Also, A-1 or B-1 is indicating inverse and "In" = for example, A-1 times A
I hope you understand the above. I have to show all the steps.
Question 2
Suppose we consider the set of all 2x2 matrices along with the operations of matrix addition and multiplication. Do they form a field? Why or why not?
I think the answer is no because under multiplication it is not commutative and not all square matrices are invertible. I not positive so I'd like some help. Penny Nom lui répond. |
|
|
|
|
|
A matrix construction problem |
2005-03-14 |
|
Marcelo pose la question : I want to know if is it possible to solve this problem:
I have an empty NxM matrix and I know totals (sum) by rows and totals by column.
Is there any algorithm to fill the matrix so that the summary of columns and rows gives the original values I have? Harley Weston lui répond. |
|
|
|
|
|
Pizza for Jack? |
2004-09-16 |
|
Grace pose la question : Jack is playing pool with Jim for $1 a game. He has only $2 and decides to play until he goes broke or has $5, at which point he will quit and go out for a pizza with Jim(Dutch treat). Jack knows from past experience that he beats Jim 60% of the time. What is the probability that Jack will get to eat pizza? Hints: Let A be the 6x6 matrix defined by A=[aij], where aij is the probability that Jack will have $(i-1)after one game is he starts with $(j-1). For example, a23 - .40 since there is a 40% probability that Jack will end up with $1 after a game is he starts the game with $2 (If Jack wins 605 of the time, he must lose 40% of the time). Also, for example, a52 = 0 since there is no way jack can have $4 after one game if he had $1 at the beginning of the game. Since Jack will stop if he goes broke or accumulates $5, a11 and a66 are both 1.
Let x0 = [0 0 1 0 0 0 ] transposed, which we interpret as saying that initially Jack has $2 with a probability 1. Then Ax0 will represent the porbability of each amount of money, $0-$5, after one game. What is the probability that Jack will be able to eat pizza by computing Akx0 for large k and finding a limiting value. Penny Nom lui répond. |
|
|
|
|
|
Row echelon form |
2004-07-24 |
|
Michael pose la question : My name is Michael and I'm in the 11th grade. I have a Math question that I can't solve. The problem is system of equations that I need to do in augmented matrix form, find the row echelon form, and solve it by using back substitution.
2x + 3y + 7z =13
3x + 2y - 5z = -22
5x+ 7y - 3z = -28 Penny Nom lui répond. |
|
|
|
|
|
Arrays |
2004-02-19 |
|
A parent pose la question : please demonstrate mathematical arrays fro a 3rd grader Penny Nom lui répond. |
|
|
|
|
|
Matrices |
2003-12-05 |
|
Julie pose la question : I am doing a project and need to find some mathematiciens who had an influence in matrices. I can't seem to find any when I search online. Could you please help me with this? Judi McDonald lui répond. |
|
|
|
|
|
A determinant |
2003-02-13 |
|
A student pose la question :
I have to find the determinant of the following matrix -2 | 3 | 1 | 2 | 4 | -3 | 0 | -2 | 5 | 1 | 4 | 2 | 1 | -3 | 5 | 2 | 3 | 4 | -1 | 2 | 6 | 0 | 3 | 2 | -4 | Penny Nom lui répond. |
|
|
|
|
|
Augmented matrix |
2002-12-31 |
|
Michelle pose la question : I am trying to augment a matrix so that i can find the values of the variables a, b, and c. For the life of me i can't find a solution to the matrix: 3 -5 2 ' 22 2 3 -1 ' -9 4 3 3 ' 1 I thank you for your help, Michelle Penny Nom lui répond. |
|
|
|
|
|
An augmented matrix |
2002-04-20 |
|
A student pose la question : Hi my math teacher asked us to solve an augmented matrix. I am in twelfth grade and need help. The book we are working on is college algebra. Here it is a+2b+c=0 2a+5b+4c=-1 a-b-9c=-5 Penny Nom lui répond. |
|
|
|
|
|
If the matrix A is inverible and AB =AC, then B = C |
2002-03-27 |
|
Vikki pose la question : i hope you can help i am soooo stuck here goes: a)
A= 0 1 B= 1 1 c= 2 5 0 2 3 4 3 4
A,B and c are matrices Evaluate AB and Ac (which I can do) then
b) I need to prove that if the matrix A is inverible and AB =AC, then B = C. Why does this not contradict what happened in part a)? Leeanne Boehm lui répond. |
|
|
|
|
|
Matrix |
2001-11-21 |
|
Hoda pose la question : I have a question about matrix multiplication; well, actually, matrix division. I am assuming that matrices are divided the same as they are multiplied; that is, row by column. But what happens if you have to divide by zero? How does this affect the resulting matrix? Patrick Maidorn and Penny Nom lui répond. |
|
|
|
|
|
Conformable matrices |
2001-08-05 |
|
Wayne pose la question : Can someone explain the concept of conformable matrices in a way that is easy to understand ? One definition says to multiply matrices rows and columns must conform, ie, 5 x 3 matrix times a 3 x 5 matrix. In the next example, however a 8 x 1 matrix and a 8 x 3 matrix are said to be conformable! Steve Kirkland lui répond. |
|
|
|
|
|
Matrix reconstruction |
2001-07-19 |
|
Guy pose la question : Is there a way to get the sums of rows, columns and diagonals of an n x n matrix to reconstruct the original matrix? Walter Whiteley and Patrick Maidorn lui répond. |
|
|
|
|
|
Matrices |
2001-03-26 |
|
Peg pose la question : What are some applications of matrices, basic trigonometry, and linear systems in the real world? I'm writing and Algebra report about where these topics are used outside of the classroom. Judi McDonald and Walter Whiteley lui répond. |
|
|
|
|
|
Solving Equations |
2001-02-23 |
|
Stephanie pose la question : Do you know who came up with solving equations? Do you have any web-sites that can give me good information on solving equations? Do you know any history on solving equations? Do you know what solving equations is used for? And finally............Sorry about all of the questions :) Has the form of solving equations changed from the time it came out to now? Juci McDonald lui répond. |
|
|
|
|
|
Where will we use this in the real world? |
2000-10-11 |
|
Jane Ann Musgrove pose la question : As a teacher of mathematics, I am always asked "Where will we use this in the real world?". I am seeking ideas/sites via the internet where students can find answers to this type of question. Can you help me? To be more specific, right now I am interested in finding careers where the employees would use the concepts of "Radicals", "Matrices", and "Logarithms". This information will be used by students to make presentations to the class on their findings from internet searches. Harley Weston lui répond. |
|
|
|
|
|
A matrix equation |
2000-05-14 |
|
A student pose la question : Right now, we are dealing with matrices and we are supposed to solve the following problem on our graphing-calculators: 2a+3b-4c+d=20 a-2b+3c-5d=-14 3a+4b-2c+3d=19 5a-b+6c+4d=-5 Penny Nom lui répond. |
|
|
|
|
|
Matrices Information |
2000-05-02 |
|
William Avery pose la question : I am an OAC student at Governor Simcoe Secondary School in St. Catharines Ontario. Today at school we were handed an independent study project by our Finite teacher. This assignment is based on Matrices, it involves performing some simple matrix calculations, but also involves a written section. This written section asks for the following: . . . Marley Weston lui répond. |
|
|
|
|
|
Taxis in Chicago |
2000-03-27 |
|
A high school studenthigh school student pose la question : Suppose that taxis pick up and deliver passengers in Chicago, which is divided into three zones. Records kept by the drivers show that of the passengers picked up in Zone 1, 50% are taken to a destination in Zone 1, 40% to Zone 2, and 10% to Zone 3. OF the passengers picked up in Zone 2, 40% go to Zone 1, 30% to Zone 2, and 30% to Zone 3. Of the passengers picked up in Zone 3, 20% go to Zone 1, 60% to Zone 2 and 20% to Zone 3. Suppose that at the beginning of the day, 600 of the taxis are in Zone 1, 100 in Zone 2, and 300 in Zone 3. What is the distribution of taxis in the various zones after all have had two riders? Harley Weston lui répond. |
|
|
|
|
|
A system of equations in five unknowns |
2000-03-20 |
|
Will pose la question : I have been having some problem with the following question for some time. I would appreciate any help on solving the problem or a solution. Q: Assume that a system of equations in the unknowns x1, x2, x3, x4 and x5 when converted to row echelon form gives . . . Penny Nom lui répond. |
|
|
|
|
|
Matricies |
1998-11-26 |
|
Stephanie Webster pose la question : If a matrix for a rectangle looks this way: AACC BDDB What does the matrix for a square look like? Penny Nom lui répond. |
|
|
|
|
|
Mathematical Arrays |
1998-05-01 |
|
Gene Lanctot pose la question : Could someone please explain what a mathematical or arithmetical array is? The array in question is used in grade three math in Ontario. I would also like to know what its purpose is. Harley Weston lui répond. |
|
|
|
|
|
Logic and Matrix Instruction |
1998-04-24 |
|
Robin Booker pose la question : I need assistance with instruction strategies to teach the construction of a matrix, solving a logic problem. Providing instruction in the construction of a simple matrix , no problem. However, I stumpted on this one. Five players were chosen as All Stars at the basketball banquet. Based on the following clues, find the player's name, team, uniform color and number of points scored.... Harley Weston lui répond. |
|
|
|
|
|
Matrices |
1998-03-10 |
|
Ksya pose la question :
- A and B are matrices. If A^n=B^n, can we say A=B or det(A)=det(B) or det(A)^n=det(B)^n ? Any conditions ???
- If B^(-1) is the inverse of B, where B is a matrices. Can we say [(B^(-1))^n][B^n]=I, where I is identity matrices? Any conditions???
Doug Farenick lui répond. |
|
|