Determinant Definition and 494 Threads

  1. W

    Variation of the metric's determinant [General Relativity, Variational Calculus]

    Hello all :) Homework Statement I'm trying to understand the fundamentals of General Relativity, but alas, I seem to be unable to grasp the fundamentals of variational calculus. Specifically, I'd like to prove the following relation for the square root of the negated determinant of the...
  2. S

    Proving Determinant of Unitary Matrix is Complex Number of Unit Modulus

    [FONT="Arial Black"][SIZE="7"]SOLVED 1. show that the determinant of a unitary matrix is a complex number of unit modulus 2. i know the equation for a determinant, but i guess to i am not sure what a complex number of unit modulus is either. I'm looking for...
  3. A

    Trace and Determinant Relationship: Proving the Relation with O(x^2)

    Hi, can anyone give me an hint to proof the relation det(I + x A) = 1 + x tr A + O(x^2) thank you.
  4. fluidistic

    Cofactor matrix and determinant question

    Homework Statement I have the matrix A as being (-2 3 2; 6 0 3; 4 1 -1) and I'd like to calculate its determinant via calculating its cofactor matrix, even if I know it's much more laborious than just calculating its determinant. I've calculated its cofactor matrix as being (-3 18 6; 5 -6...
  5. fluidistic

    Linear algebra : calculating the determinant

    -1. Homework Statement Let A and B be 2x2 matrices such that A²B=3I and A^T*B³=-I, where A^T is the transposed matrix of A, and I is the identity matrix. Calculate det(A). 0. The attempt at a solution I know I don't know how to approach correctly the problem, but I've tried something. I...
  6. D

    Solving Determinant Question for 3A2B-1

    i am given 2 matrices A= a1 b1 c1 a2 b2 c1 a3 b3 c3 B= -c2 3c1 -c3 b2 -3b1 b3 -5a2 15a1 -5a3 and also given is: 5detA+detB=10 what i need to fin is det(3A2B-1) what i did to help me was det(3)=27...
  7. K

    Isomorphism: matrix determinant

    Determine whether the given map \varphi is an isomorphism of the first binary structure with the second. < M2(R ), usual multiplication > with <R, usual multiplication> where \varphi(A) is the determinant of matrix A. The determinant of the matrix is ad-bc, so \varphi(A)=ad-bc. For this...
  8. O

    Christofle symbol and determinant of metric tensor

    Hi, every one I'm newbie here. I have a few problem with my study about GR. Here's a problem \partial_a(g^{ad})g_{cd}-\partial_d(g^{ad})g_{ac}=\\0 Could I prove these relation by change index (in 1st term ) from a -> d and also d -> a? and let's defined {g}=det{\\g_{ab}\\}...
  9. F

    Determinant Functions in 3x3 Matrices for A, B, and I

    Homework Statement Let A be a 3 x 3 matrix. Consider the function f(A) = a11a22a33; g(A) = a11 a12 a13 and h(A) =1. Show that each of these is not a determinant function. Homework Equations det(I) = 1 det(B) = det(A) (if B is obtained from adding a mutiple of one row of A to another...
  10. S

    Where Am I Going Wrong with the Secular Determinant in MO Method?

    Not a problem par se, as much as me failing somewhere in algebra, and i can't find my mistakes. Trying to work through the secular determinant E_\pm = det\left( \begin{array}{cc} \alpha - E & \beta - ES\\ \beta - ES & \alpha - E \end{array}...
  11. S

    About the Jacobian determinant and the bijection

    Hello! I am having problems with the inverse function theorem. In some books it says to be locally inversible: first C1, 2nd Jacobian determinant different from 0 And I saw some books say to be locally inversible, it suffices to change the 2NDto "F'(a) is bijective".. How could these two be...
  12. J

    Difficult polynomial and determinant formula

    Anyone having any ideas about how this formula could be proved? \underset{k<l}{\prod_{k,l=1}^n} (x_k - x_l) = (-1)^{n(n-1)/2} \left|\begin{array}{ccc} 1 & \cdots & 1 \\ x_1 & \cdots & x_n \\ \vdots & & \vdots \\ x_1^{n-1} & \cdots & x_n^{n-1} \\ \end{array}\right| I tried...
  13. L

    Linear Algebra - Determinant Properties

    Homework Statement 1. Give an example of a 2x2 real matrix A such that A^2 = -I 2. Prove that there is no real 3x3 matrix A with A^2 = -I Homework Equations I think these equations would apply here? det(A^x) = (detA)^x det(kA) = (k^n)detA (A being an nxn matrix) det(I) = 1 The...
  14. A

    Answer 4x4 Determinant: a+b+c+d

    Homework Statement The determinant a+1 a a a b b+1 b b c c c+1 c d d d d+1 equals =? option : a) 1+ a + b+ c+ d b)a + b+ c+ d c)a.b.c.d d)1 + a.b.c.d Homework Equations The Attempt at a Solution [1] tried using finding...
  15. S

    Can the 'Determinant' be Reversed for 2-by-2 Matrices?

    Let there be a 2-by-2 matrix A with the elements: [a b] [c d] Now, let there be a 2-by-2 matrix B with the elements: [w x] [y z] Let A*A = B. This means that w, x, y, and z can all be independantly represented solely in terms of a, b, c, and d. My question: is there any way...
  16. S

    Determinant formula in monomials - can it be generalized?

    Determinant formula in monomials -- can it be generalized? I ran across this question in one of the Usenet groups (fr.sci.maths), and after doing a double take and realizing what was actually being asked I realized I don't know the answer, and after searching a bit I haven't turned it up, so I...
  17. T

    Odd Determinant: Explaining a Strange Phenomenon

    I don't understand this : let A is n x n matrix whose entries are precisely the numbers 1, 2, . . . , n^2. Put odd numbers into the diagonal of A, only even numbers above the diagonal and arrange the entries under the diagonal arbitrarily. Then det(A) is odd. What is the explanation ?
  18. B

    Why is energy the ultimate determinant of spontaneity

    I understand that a chemical reaction is spontaneous if it has a (-) gibbs free energy = if it is endergonic. My question is: Why is energy the ultimate determinant of spontaneity
  19. N

    Cross product in matrix determinant form

    Everything I have read indicates that the cross product is simply defined as a x b = i( ay*bz - az*by) - j( ax*bz - az*bx ) + k( ax*by - ay*bx ) and that it just so happens that there is a shorthand notation of cross product in matrix determinant form. How is the cross product...
  20. T

    Factoring Determinant of 3x3 Matrix - Step by Step Solution

    Homework Statement | x x^2 1 | | x^2 x 1 | | x^3 x^3 1 | The answer is = x^2(1-x)^2(1+2x) Homework Equations none The Attempt at a Solution By factoring the matrix step by step. Thanks :)
  21. F

    Linear Algebra Question: Determinant

    The question on my homework says: What can you say about the graph of the equation The following is in matrix form with determinant symbols around the matrix x y 1...
  22. Z

    Proving Let A & B be Square Matrices of n x n & AB = 0n

    Need some help on how to prove this: Let A and B be two non-zero square matrices of n x n, if AB = 0n, then det(A) and det(B) must both equal to 0. I know if det(AB) = 0, then det(A) or det(B) must be 0, but here the question states that they must both be 0. Appreciate any help, thanks.
  23. rocomath

    Determinant of 4 x 4 Upper-triangle: 36

    Ok, I have gotten different answers by reducing to an upper triangle, co-factor, and my calculator. All 3 giving me different answers! |Upper-triangle| = lol, was looking at the wrong problem ... I did get 36. |Co-factor reduction mobob| = uh i keep messing it up |Calculator| = 36 1 2 3 0 2 6...
  24. Z

    What is the formula for finding the determinant of a 10x10 matrix?

    I am trying to figure out the formula for the determinant of a 10x10 matrix. I was told to use row reducation method, but I am not really sure what it is. I never took Linear Algebra. Can someone please help me.
  25. R

    How do you find the determinant

    http://users.on.net/~rohanlal/11Untitled.jpg How do I find the value of a for which there will be no solution? Do you find the determinant, equate it to 0 and solve for a?
  26. R

    Determinant of linear transformation

    Homework Statement symmetric 2 × 2 matrices to V.Find the determinant of the linear transformation T(M)=[1,2,2,3]M+[1,2,2,3] from the space V of symmetric 2 × 2 matrices to V. Homework Equations The Attempt at a Solution hi this is my first post so if I break a rule please...
  27. P

    Linear algebra determinant of linear operator

    [SOLVED] linear algebra determinant of linear operator Homework Statement Let T be a linear operator on a finite-dimensional vector space V. Define the determinant of T as: det(T)=det([T][SIZE="1"]β) where β is any ordered basis for V. Prove that for any scalar λ and any ordered basis...
  28. K

    How to Find the Determinant of a Matrix in C for Newton Gregory Method?

    Can somebody help me in finding a determinat of a matrix of any dimension using C? This is in order to form an interpolating formula using the Newton Gregory Method.
  29. N

    What Does a Determinant of 1 in a Transformation Matrix Signify?

    Does it mean anything in particular about the transformation if the determinant of a transformation matrix is 1?
  30. B

    Calculating the determinant of a quadratic for Eigenvalues

    Homework Statement Find the eigenvalues and eigenvectors of A = \left(\begin{array}{ccc}5&1&1\\1&3&1\\1&1&3\end{array}\right) The Attempt at a Solution The problem I'm having is finding the eigenvalues for the matrix. In 2d matricies it's not too bad, but in 3d the...
  31. L

    Determinant of rotation matrices

    Hi, After obtaining the 2D rotation matrix (as a function of rotation angle) once by geometry and once by complex algebra, I tried to obtain it by invariance of the Euclidean metric. By this approach, the four elements of the 2D rotation matrix can be determined in terms of a single...
  32. H

    Determinant Expansions: Intuitive Understanding & Proofs

    Hi, I can't understand why any determinant expansion is the same via any row/column. My lecturer says the proof is too technical to go over, Does anyone have a good way to think about it intuitavely or know a site which has a full proof? thnx
  33. S

    How Does Changing Rows Affect a 4x4 Matrix Determinant?

    If a 4X4 matrix A with rows v1, v2, v3, and v4 has determinant det A = -8 then det |(4v1+3v4)| |___v2___| |___v3___| =? |(8v1+9v4)| - I put the underscores for spacing.The Attempt at a Solution - I haven't attempting anything on this problem. There are no examples even remotely like this...
  34. S

    How do you find the determinant of a 3x3 matrix with polynomial equations?

    M= |3-2x^3_____-4+2x^2+4x^3______0| |-x^3________1+x^2+2x^3_______0| |-8-6x^2_____16+12x^2____-1-3x^2| find the determinant. * I put the underscores for spacing.The Attempt at a Solution I first tried finding det(A) as if it was a regular matrix of numbers, but that doesn't...
  35. H

    Matrix determinant proof problem

    Homework Statement I have to proove that the determinant of : x a a . . . a a x a . . . a . . . . . . a . . . a a . . . . . x If you get the idea (it's (n x n) with x's along the diagonal and a's everywhere else) That it is (x + (n-1)a)(x - a)^(n-1)...
  36. A

    4x4 determinant using upper triangular form

    [SOLVED] 4x4 determinant using upper triangular form Homework Statement |2 0 1 4| |3 2 -4 -2| |2 3 -1 0| |11 8 -4 6| Homework Equations Ive done this a number of times and i still can't get the answer. I ended up w/ 275, but the answer is suppose to be zero The...
  37. G

    Understanding Determinants: Calculation and Function

    What does a determinant do exactly (what is it)? And what is the general method of calculating it?
  38. E

    Probability a determinant is odd

    [SOLVED] probability a determinant is odd Homework Statement The elements of a determinant are arbitrary integers. Determine the probability that the value of the determinant is odd. (Hint: Work mod 2).Homework Equations The Attempt at a Solution When n=1, the probability is 1/2. When n = 2...
  39. E

    Prove A Orthogonal $\Rightarrow$ |A|=+-1

    Prove if A is orthogonal matrix, then |A|=+-1 A^{-1}=A^{T} AA^{-1}=AA^{T} I=AA^{T} |I|=|AA^{T}| 1=|A|*|A^{T}|//getting to the next step is where i get confused. Why is |A|=|A^{T}| 1=|A|*|A| 1=|A|^{2} +-1=|A|
  40. E

    Proof of Determinant: Need Help?

    I need help with proof. Can anyone lead me in the right direction? http://i153.photobucket.com/albums/s208/nailbomb2/LastScan.jpg
  41. S

    What are the possible values of the determinant of an orthogonal matrix?

    Hi I had a final today and one of the questions was find all the possible values of det Q if Q is a orthogonal matrix I m still wondering how would I do this? Any ideas?
  42. F

    What is the best method to get a matrix into upper triangular form?

    [SOLVED] Determinant of Matrices Find the det. of the matrix: 1 3 -2 2 3 0 -1 4 1 -3 4 2 2 3 -3 3 Using gaussian elimination to get it into upper triangular form (which I think is easiest) is where I am struggling. I get as far as: 1 3 -2 2 0 -9 5 -2 0 -6 6 0...
  43. S

    Solving Determinants: Tips for Midterm Exam

    Hi, I have a midterm tomorrow for my Lin Alg course and I was doing some review probs and I can't seem to understand this one.. http://img119.imageshack.us/img119/239/39786409wb4.jpg Can someone help me and explain how to do this one! I know I can just find the whole vector...
  44. K

    Determinant of a Hermitiain matrix

    Q: Suppose A is a Hermitiain matrix, prove that det A is real. Note: I know nothing about inner products yet. Some thoughts: Perhaps proving that det A = conjugate of (det A) ? But how? Can someone please help me? Thanks!
  45. E

    Determinant Question: Show det(M) = det(A) det(D)

    Homework Statement A is a k by k matrix, B is a k by l matrix, D is an l by l matrix. Let M be the (k+l) by (k+l) matrix that has A in the upper left, B in the upper right, D in the lower right, and 0 in the lower left. Show that det(M) = det(A) det(D)Homework Equations The Attempt at a Solution
  46. H

    Zero determinant - Can we make a zero column?

    I just wanted to know that the following statement is always true or not. After I expand the determinant I get the value of the determinant as zero, ie. I know that the value of the determinant zero. Then with the help of row or column transformations can we transform the determinant into...
  47. K

    Determinant of a matrix multiplied by a scalar

    Homework Statement it is problem 1 on the attachment Homework Equations detA = ad - bc for a 2 x 2 matrix, where the first column is a c and the 2nd column is b d The Attempt at a Solution ah i see the first part i think, but I am nto sure I am writing my answer in the most...
  48. V

    Solved: Det of 4A-1 | Find Det of 4A-1 Matrix

    [SOLVED] Determinant problem Homework Statement If det(A) = 7, then what is det(4 A-1)? where A is 3*3 matrix Homework Equations The Attempt at a Solution No idea about this, please give me some hint.
  49. S

    Functional determinant approach to perturbation

    given the functional integral with 'g' small coupling constant \int \mathcal D [\phi]exp(iS_{0}[\phi]+\int d^{4}x \phi ^{k}) so k >2 then could we use a similar 'Functional determinant approach' to this Feynman integral ?? in the sense that the integral above will be equal to...
  50. K

    Understanding Functional Determinants in Mathematics

    I say what is a functional determinant ?? for example Det( \partial ^{2} + m) is this some kind of Functional determinant? then i also believe (althouhg it diverges ) that Det( \partial ^{2} + m)= \lambda_{1}\lambda_{2}\lambda_{3}\lambda_{4}... (the determinant of a Matrix is the...
Back
Top