Questions tagged [determinant]
Questions about determinants: their computation or their theory. If $E$ is a vector space of dimension $d,ドル then we can compute the determinant of a $d$-uple $(v_1,\ldots,v_d)$ with respect to a basis.
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2
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1
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Why is fact that the determinant of this matrix is 0 equivalent to $x'^T Fx=0$
I am reading Multiple View Geometry in Computer Vision and in the chapter 17.1, it talks about the following matrix which needs to have 0ドル$ determinant.
$$
\begin{bmatrix}
A & x & \textbf{0} \\...
0
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0
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Check proof that the determinant of a polynomial matrix commute with evaluation
This is used in one of the many proofs for the Cayley-Hamilton theorem. My professor noted that this should be proved. However, the proof of this fact is rather straightforward, no? Is the proof I ...
1
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0
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42
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Ideal of maximal minors is radical when rank never drops by more than 1 [Reference request]
Let $R := \mathbb C[x_1,\dots,x_d]/J$ be an affine domain which is the coordinate ring of the affine variety $X = V(J) \subseteq \mathbb C^d$. Let $M \in R^{m\times(n+1)}$ be a matrix with entries ...
0
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1
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Is using determinants like this for vector algebra standard?
It is known that, $$
\nabla \cdot (\mathbf{A} \times \mathbf{B}) = \mathbf{B} \cdot (\nabla \times \mathbf{A}) - \mathbf{A} \cdot (\nabla \times \mathbf{B})
$$
The straightforward way to prove this ...
0
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A quest about the determinant of a skew symmetric matrix [duplicate]
Prove that the determinant of a skew-symmetric matrix of even order does not change if to all its elements we add the same number.
i tried calculating $\det(A+cB),ドル$c \in R,ドル $(b)_{ij}=1 \forall i,j$ ...
3
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1
answer
232
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Mathematical Proof from "Linear Algebra" by Werner Greub
This is a problem from Linear Algebra by Werner H. Greub in Chapter 4:
Let $V^*,ドル $V$ be a pair of dual spaces (${\rm dim}V={\rm dim}V^*=n$) and $\Delta \neq 0$ be a determinant function in $V$. ...
0
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1
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100
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Cofactor of a tensor
In the book that I’m actually using for tensor algebra (second order tensors in $\mathbb{R}^3$), the author defines the cofactor of a tensor as the tensor that transforms the area vector, that is, ...
4
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1
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163
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Rank of $A+tB+t^2C$ is a constant almost everywhere
Let $A,ドル $B,ドル and $C$ be three $m \times n$ matrices, and define $A(t)
= A + t B + t^2C$ as well as $f(t) = \operatorname{rank}(A(t))$. Then $f(t)$ is a constant over $\mathbb{R}$ except finite values ...
3
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1
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Area of Parallelogram when Determinant = 0.
I am familiar with basic introductory Linear Algebra. I know that the determinant of a 3x3 matrix gives you the volume of the parallelepiped formed by the coordinate vectors after the transformation. ...
7
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0
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Computing the determinant of a tridiagonal matrix
I want to compute in a nice way the determinant of a $(n+1) \times (n+1)$ tridiagonal matrix $M_n$ for odd $n$. For $n=7,ドル the 8ドル \times 8$ matrix is
$$ M_7 = \begin{pmatrix}
7u & -2 & 0 & ...
1
vote
0
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34
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Degree-$k$ part of a structured determinant as a linear combination of minors?
Fix an integer $d\ge 2$. Let $x_1,\dots,x_{2d}$ be variables, and let
$t_1,\dots,t_{2d}$ and $u_1,\dots,u_{2d}$ be parameters. Consider the
2ドルd\times 2d$ determinant
$$
F_d(x;t,u):=\det\begin{pmatrix}
...
13
votes
1
answer
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Is there such a mathematical notion as 'antideterminant'?
The determinant of a matrix is given by the Leibniz formula
$$\det(A) = \sum_{\tau \in S_n} \text{sgn}(\tau) \prod_{i = 1}^n a_{i\tau(i)} = \sum_{\sigma \in S_n} \text{sgn}(\sigma) \prod_{i = 1}^n a_{\...
2
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0
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37
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Non-trivial lower bound for minimum non-zero determinant among square submatrices
Let $A \in \mathbb{R}^{m, n},ドル with $n > m$ and $\text{rank}(A) = m,ドル and let $\mathcal{B}$ be the set of square $m\times m$ submatrices of $A$.
In other words, $\mathcal{B}$ contains all matrices $...
5
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3
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181
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Determinants of two matrices and their sum, entries are consecutive primes
In general determinants are not additive (related question). Nevertheless, matrices $A$ and $B$ can be chosen so that $\det A+\det B=\det\left(A+B\right)$ (related answer).
For which positive integer ...
1
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0
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38
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Cubic part of a 6ドル\times6$ determinant via $\Delta(ijkm)?$
Let $a_i,b_i,c_i$ be parameters and $x_1,\dots,x_6$ variables. Consider
$$
D=\begin{vmatrix}
a_1^2(a_1x_1+c_1) & a_1(a_1x_1+c_1) & a_1x_1+c_1 & x_1+b_1 & a_1(c_1-a_1b_1) & c_1-...