Determinant Definition and 494 Threads

  1. T

    Mastering Determinants: A Scientist's Approach to Solving Equations

    Homework Statement Homework Equations The Attempt at a Solution
  2. D

    MHB Determinant Property: Seen it Before? True?

    Has anyone seen this before? Is this true? $$ \begin{vmatrix} a & b+c & 1\\ b & a+c & 1\\ c & a+b & 1 \end{vmatrix} = \begin{vmatrix} a & b & 1\\ b & a & 1\\ c & a & 1 \end{vmatrix} + \begin{vmatrix} a & c & 1\\ b & c & 1\\ c & b & 1 \end{vmatrix} $$ In this example this works but I don't know...
  3. R

    Determinant of a Finite Field 2x2 Matrix

    Homework Statement Find the determinant of: |1 1| |2 1| The field is Z3. Homework Equations The field is Z3, that is, to multiply two numbers, you first multiply then take the remainder of the division by 3. The Attempt at a Solution I tried: ( 1 x 1 ) - ( 1 x 2 ) 1 x 1 will...
  4. X

    Phys Orgo Secular Determinant question

    Homework Statement Solve for the wavefuntions using the Secular Determinant, of cyclopropene anion/cation/whocares. Homework Equations Secular determinant: | x 1 1| | 1 x 1| |1 1 x | The Attempt at a Solution I'm literally understanding every aspect of this concept, but...
  5. Petrus

    MHB What is the expression for |c_n| in terms of the given matrice?

    Matrice $$c_n$$ is a 2nxn2 matrice and is given by $$(\delta_{ij}+2\delta_{i,2n-j+1})_{ij}$$ determine the expression of $$|c_n|$$ progress: I have been drawing the matrice $$n=1,2,3$$ and calculate the determinant. As you see there is a pattern with the matrice and I would like to have tips...
  6. T

    Determinant of a 4x4 Matrix - Check my answer please?

    Homework Statement Hey guys, I usually have no trouble with 3x3 matrices, and for a 4x4 I've a rough idea how to do it but not entirely sure if I did it correct. I've attached my attempt below with working out. The matrix: \begin{pmatrix} 0 & 2 & 0 & 0 \\7 & a+1 & 3 & a+1 \\1 & 0 & 2 &...
  7. B

    Determinant of Functions and Analyticity

    Homework Statement Homework Equations The Attempt at a Solution I have already proved that ## N(T) \supset span\{y_{1},y_{2},...y_{n} \} ## but am having trouble proving the other half. You can't use the fact that the determinant is 0 to conclude that functions are linearly dependent unless...
  8. I

    Jacobian Determinant/ mult. variable implicit differentiation

    Homework Statement Let F: x^2 + y^2 - z^2 + 2xy - 1 = 0 and G: x^3 + y^3 - 5y - 4 = 0. Calculate dz/dx. Note: This is NOT the partial derivative ∂z/∂x. I do not need help in taking the derivative of many polynomials. What I need help in is setting up a Jacobian determinant to evaluate this...
  9. E

    Cauchy expansion of determinant of a bordered matrix

    The Cauchy expansion says that \text{det} \begin{bmatrix} A & x \\[0.3em] y^T & a \end{bmatrix} = a \text{det}(A) - y^T \text{adj}(A) x , where A is an n-1 by n-1 matrix, y and x are vectors with n-1 elements, and a is a scalar. There is a proof in Matrix Analysis by Horn and...
  10. B

    If two matrices have the same determinant, are they similar?

    If two matrices are similar, it can be proved that their determinants are equal. What about the converse? I don't think it is true, but could someone help me cook up a counterexample? How does one prove that two matrices are not similar? Thanks! BiP
  11. C

    Basic Multivariable Proof Equating Determinant to dot/cross product

    Hello folks! Just a concise introduction of myself before I get to the task at hand: I'm new to these forums although I have been surfing them frequently for the past 5 years! I am not a math major and quite frankly, my skills in the subject are limited. Be that as it may, my fascination for...
  12. A

    Optimizing Sudoku Determinants: Finding the Minimum and Maximum Values

    Homework Statement A while ago someone posted this problem: ----------------------------------------------------------------------------------- Problem 1 (given after a discussion of determinants in week 3/4 of the course): Consider a 9x9 matrix A. We say that A is a Sudoku matrix if it's...
  13. Petrus

    MHB What Are the Rules for Determining the Determinant of a 4x4 Matrix?

    Hello MHB, calculate determinant of: $$ \left| {\begin{array}{cc} 2 & -2 & -3 & 8 \\ 1 & -1 & 2 & -1 \\ -3 & 4 & 1 & -1 \\ -2 & 6 & -4 & 19 \end{array} } \right|$$ so I multiplication -2 row 2 and add it to row 1, multiplication 3 to row 2 and add it to row 3, multiplicate 2 to row 2 and add...
  14. Z

    Determinant of the electromagnetic matrix

    hi there, In this wikipedia article https://en.wikipedia.org/wiki/Electromagnetic_tensor we have the following invariant : FαβFμη [SIZE="3"]εαβμη = 8 E*B However the determinant is the square of this quantity divided by 8, i.e. ( E*B )2 . Now from the definition of the determinant...
  15. U

    Determinant of an n x n matrix

    Homework Statement Find the determinant of the matrix given by: \begin{array}{ccc} 1 & 2 & 3 & ... & n \\ 2 & 2 & 3 & ... & n \\ 3 & 3 & 3 & ... & n \\ . & . & . & & . \\ . & . & . & & . \\ . & . & . & & . \\ n & n & n & ... & n \end{array} Homework Equations We...
  16. M

    Slater Determinant & Permanent

    How to use Slater determinant and permanent to find out whether the state is symmetrical or anti-symmetrical? How to use them? I got the concept but I didn't get for example when to know if there was a plus or a minus and thus whether what we're talking about is a permanent or determinant...
  17. N

    Determinant in Transformation from spherical to cartesian space

    Homework Statement Evaluate the appropriate determinant to show that the Jacobian of the transformation from Cartesian (this is a typo, they mean spherical) pψθ-space to Cartesian xyz-space is ρ2sin(ψ).Homework Equations The Attempt at a Solution Uhm, I am lost. I'm supposed to prove that when...
  18. T

    Determinant Function: Understanding Orientation

    I am curious on how the determinant function determines orientation? I read about in in one of Werner greubs books and I just cannot manage to understand what it is
  19. J

    How Can You Represent Determinants Using Permutations?

    it seems to have many different ways to express a determinant, when we are using indices to write vectors and tensors, e.g. in General Relativity. is there any summary about how to express a determinant, for example, in Levi-Civita Tensor and so on?
  20. S

    Proof that Determinant is Multiplicative for Commutative Rings

    Is there a nice way to show that Det(AB)=Det(A)Det(B) where A and B are n x n matrices over a commutative ring? I'm hoping there is some analogue to the construction for vector spaces that defines the determinant in a natural way using alternating multilinear mappings... Otherwise would...
  21. caffeinemachine

    MHB Gcd of polynomials is 1. There is an nxn matrix with determinant....

    Let $F$ be any field. Let $p_1,\ldots, p_n\in F[x]$. Assume that $\gcd(p_1,\ldots,p_n)=1$. Show that there is an $n\times n$ matrix over $F[x]$ of determinant $1$ whose first row is $p_1,\ldots,p_n$. When $n=2$ this is easy since then there exist $a_1,a_2\in F[x]$ such that $p_1a_1+p_2a_2=1$...
  22. F

    Differents answers to the same determinant

    Homework Statement Lets find the determinant of 1 1 1 1 ... 1 1 2 2 2 ... 2 1 2 3 3 ... 3 1 2 3 4 ... 4 ... 1 2 3 4 ... n The Attempt at a Solution In class, we solved it by subtracting the previous line of every single line, ending up with 1 1 1 1 ... 1 1 2 2 2 ... 2...
  23. J

    How to manipulate the determinant of metric tensor?

    How to calculate something relating to the determinant of metric tensor? for example, its derivative ∂_{λ}g. and how to calculate1/g* ∂_{λ}g, which is from (3.33) in the book Spacetime and Geometry, in which the author says that it can be related to the Christoffel connection.
  24. mishima

    Determinant Zero, Saturated Bipolar Transistor

    Homework Statement I am looking for the base, collector, and emitter voltages in the following circuit: Homework Equations KCL KVL offset voltage = VB - VE saturation voltage = VC - VE The Attempt at a Solution First I made a matrix without assuming any values for offset or...
  25. L

    Determinant of product of matrices

    Do you know where can I find proven identity det(AB)=det(A)det(B) using Levi Civita symbol.
  26. P

    Varying determinant of a metric

    Hi can anyone explain how to find \delta \sqrt{-g} when varying with respect to the metric tensor g^{\mu\nu}. i.e why is it equal to \delta \sqrt{-g} = -\frac{1}{2} \sqrt{-g}g_{\mu\nu} \delta g^{\mu \nu}
  27. M

    Linear algebra determinant proof

    Homework Statement Let A and B be nxn matrices. Prove that if AB=I, then BA=I det(AB)=det(I) 1.det(A)*det(B)=1 det(BA)=det(I) 2.det(B)*det(A)=1 Equating 1 and two together I get det(B)*det(A)=det(A)*det(B) Thus AB=I, then BA=I Is this correct? Homework Equations...
  28. M

    Linear algebra adjoint, determinant

    Homework Statement Given A=[1 2 1; 0 4 3; 1 2 2] determine the (2,3) entry of A-1 by computing a quotient of two determinants. This problem confused me a bit, do they just want us to divide the adj(A) by the det(A) in order which would give us A-1 and just state the (2,3) entry from...
  29. P

    Varying determinant of a metric

    Hi does anyone know how to calculate: \delta (det|g_{\mu\nu}|) or simply \delta g
  30. L

    Determinant of the metric tensor

    We are stating with equivalence principle that passing locally to non inertial frame would be analogous to the presence of gravitational field at that point, so g^'_{ij}=A g_{nm} A^{-1} where g' is the galilean metric and g is the metric in curved space, and A is the transformation which...
  31. B

    Why is a matrix singular if the determinant is zero?

    I'm looking for the deeper meaning behind this law/theorem/statement (I don't know what it is, please correct me). My textbook just told us a matrix is not invertible if the determinant is zero.
  32. B

    Jacobian determinant in multiple integration

    In what kind of math course would one learn the proof of the theorem that introduces the Jacobian to computing multiple integrals under various transformations? My calculus textbook has this theorem, and uses it to derive the triple integral formulas for cylindrical and spherical coordinates...
  33. F

    Derivative of Log Determinant of a Matrix w.r.t a scalar parameter

    Hi All, I'm trying to solve the following derivative with respect to the scalar parameter \sigma $$\frac{\partial}{\partial \sigma} \ln|\Sigma|,$$ where \Sigma = (\sigma^2 \Lambda_K) and \Lambda_K is the following symmetric tridiagonal K \times K matrix $$ \Lambda_{K} = \left(...
  34. C

    Determinant using Laplace expansion

    Hello! Do somebody know where the code for calculating a determinant by Laplace theorem (in Fortran) can be found? Or maybe somebody could help with this issue. Thank you!
  35. O

    Proving Symmetric Matrix Determinant is Null

    Hi, I'm tutoring someone on lineal algebra (upper high-school level). We're going through some exercises, but we're stuck with a trivial looking one. Homework Statement Show that the following determinant is null: \left| \begin{array}{ccc} 1 & \cos x & \cos 2x \\ \cos x & \cos 2x &...
  36. Q

    A determinant containing a variable

    Homework Statement I have this 4x4 determinant and usually these are just mechanical work, until I stumbled upon one containing x, how should one go about solving these type of determinants? [x 2x 4 x ] [1 2 2x 1 ] [2x x-1 2 3x] [ 2 x+1 x+3 x-1] What are the different values of...
  37. A

    MHB Prove there exists a matrix with certain entries and determinant

    Hi. Here is a problem I found in my algebra book and I don't know how to solve it. Could you please help me? Show that there exists a matrix A \in M(n,n;R), such that m_{ij} \in \{-1,0,1\} and det A=1995 (I think it can be any other number as well, but the book was printed in 1995 :) ) My...
  38. P

    Closed-form determinant of a hermitian banded toeplitz matrix

    Hello everyone, I found that you're actively discussing math problems here and thought to share my problem with you. [Givens:] I have a specially structured complex-valued n \times n matrix, that has only three non-zero constant diagonals (the main diagonal, the j^{th} subdiagonal and the...
  39. P

    Solve 3x-y+2z=4 - Help for Newbie

    am not a math guru :P,am a newbie even if this should be solved by a newbie as well, Id like u guys to help me out to solve this one : 3x-y+2z=4 Im really needing this, thank you all.
  40. J

    Intuitive explanation for the general determinant formula?

    Hello Could anyone give an intuitive explanation of the determinant? I know mostly what the determinant means and I can calculate it etc. But I have never got any real-world intuitive explanation of the general formula of the determinant? How is the formula derived? Where does it come...
  41. P

    Determinant of a general matrix with variables.

    Hi, Homework Statement I was asked to find the determinant of the following two matrices (please see attachment). Homework Equations The Attempt at a Solution I know that the determinant of the matrix on the left is [(-1)^(n-1)]*(n-1), but I have no idea how to formally derive...
  42. L

    Determinant of enlarged Correlation Matrix

    Determinant of "enlarged" Correlation Matrix Hi guys, I am not a physicist but saw that you guys are actively discussing math problems in this forum. I have the following problem that I've been fighting with for some time now: I have a n-dimensional (n >= 3) correlation matrix with the...
  43. C

    How do I solve a Jacobian problem involving a determinant?

    Not sure if this is where I should put this but currently I am taking math for econ and we are on special determinants (jacobian, Hessian, Bordered Hessian, some Leontiff) So I have this problem in my notes that I am basically basing my exam studying around since the book isn't the best. It...
  44. I

    Variation of the metric tensor determinant

    Homework Statement This is not homework but more like self-study - thought I'd post it here anyway. I'm taking the variation of the determinant of the metric tensor: \delta(det[g\mu\nu]). Homework Equations The answer is \delta(det[g\mu\nu]) =det[g\mu\nu] g\mu\nu...
  45. D

    Matrix algebra - Gauss 0=0, determinant = 0

    Homework Statement Mesh Analysis, find current z: A= \left(\begin{array}{ccc}+30x&-15y&-15z\\-15x&+30y&-15z\\-15x&-15y&+30z\end{array}\right) b= \left(\begin{array}{c}+10\\-10\\0\end{array}\right) Homework Equations A*x=b A= resistance x= currents b= voltage sources Gauss elimination...
  46. mnb96

    Question on Jacobian determinant

    Hello, it is true that linear transformations have constant Jacobian determinant. Is the converse true? That is, if a transformation has constant Jacobian determinant, then is it necessarily linear?
  47. B

    Determinant is independent of row/column

    I am curious about the proof of the fact that the value of a determinant computed using the Laplace (or cofactor) expansion is independent of along which row (or column) the expansion is performed. Is this a very difficult proof? My textbook omits it entirely. I was curious if someone could...
  48. R

    How can I write the determinant as traces in this paper on complex matrices?

    I am reading the paper http://arxiv.org/abs/hep-th/9701037. In equation (2), the author write the determinat as traces, but I don't know how to do this. I know that ##det(e^A)=e^{tr(A)}##, where ##A## is a complex matrix, and ##det(A)=e^{tr(L)}##, where ##e^L=A## and ##L## is also a complex...
  49. K

    How to find the value of λ inside a 4x4 matrix that results in determinant = 0

    Homework Statement As you can see from the picture below this a 4x4 matrix with an unknown value, λ. My objective here is to find four values for λ so that the determinant of the 4x4 matrix is equal to zero. http://i49.tinypic.com/n4cenn.png Homework Equations The above 4x4 matrix is the...
  50. B

    How Can I Solve a Complex Determinant Problem for an nxn Matrix?

    Homework Statement The problem is attached due to it not being able to copy over the given matrix.. Number 5.3 Homework Equations The Attempt at a Solution I tried to compute A+tI and then row reduce until A+tI was a triangle matrix and then multiply the diagnol entries but I got...
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