Arnaud D.'s user avatar
Arnaud D.'s user avatar
Arnaud D.'s user avatar
Arnaud D.
  • Member for 8 years, 10 months
  • Last seen more than a month ago
  • Czech Republic
1 vote

Statement: $Ax=b$ has a solution if and only if $A^T A x = A^T b$ has a solution

1 vote
Accepted

Trouble Showing the Naturality of an Adjunction induced by $\langle F, G, \eta \rangle$

1 vote
Accepted

Clarification on the eigenspace of a rotation matrix and its implication in representation theory of the symmetric group

1 vote

Continuity of a function such that $\lambda f(x) = f(\lambda x) $

1 vote

Sum of tensor product of orthogonal basis

1 vote

Assume that $f,g \in L_{10}(\mu)$. Prove that their product $fg$ belongs to $L_5(\mu)$.

1 vote

Is there a name for relations with this property?

1 vote

Does $a_n + b_n \to c$ and $a_{n_j}, b_{n_j} \to a,b$ imply that $a_n, b_n \to a,b$?

1 vote
Accepted

Canonical isomorphism from coimage to image iff regular epi - regular mono factorization?

1 vote
Accepted

Find an explicit isomorphism between $H\rtimes_{\phi} K$ and $S_3$.

1 vote

A sequence, whose all possible finite sub sums are bounded, converges

1 vote

Prove that $\langle AA^t v, v\rangle = \langle A^t v, A^t v\rangle $

1 vote

Basic category theory: applying natural transformations

1 vote
Accepted

In a nice protomodular category, is normality stable under joins?

1 vote
Accepted

Doubt about a theorem on Direct Sums.

1 vote
Accepted

Defining homomorphism in a function.

1 vote

Understanding why Lagrange Interpolation works

1 vote
Accepted

What is wrong with my approach to find an unknown map?

1 vote

Why does WolframAlpha give different answers for these two equivalent limits?

1 vote
Accepted

Is the vector $3 + x^2$ in the subspace spanned by $\sin^2 x$ and $\cos^2 x $?

1 vote
Accepted

Is such a polynomial irreducible?

1 vote
Accepted

If $\langle x_n\rangle$ satisfies $\|x_{n+2} - x_{n+1}\| \lt \|x_{n+1} - x_n\|$, can it be a Cauchy sequence?

1 vote
Accepted

Counting the possible pairs problems

1 vote
Accepted

Jordan form in $SL_2(\Bbb C)$

1 vote
Accepted

In a preadditive category, products are coproducts

1 vote
Accepted

Row-sums of the left inverse of a matrix with non-constant row-sums

1 vote
Accepted

How can you solve tasks like that (matrices, linear mapping)?

1 vote
Accepted

Find minimal polynomial

1 vote

A question about not not diagonalizable matrix

1 vote
Accepted

Check if there is any isomorphism between two given groups