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Jan
  • Member for 4 years, 4 months
  • Last seen more than a week ago
  • Deutschland
13 votes
Accepted

Eigenvalues of a matrix whose square is zero

10 votes

Can't argue with success? Looking for "bad math" that "gets away with it"

7 votes
Accepted

Prove that $T$ is invertible if and only if $0$ is not an eigenvalue of $T$

7 votes

Prove that sum of matrices equals zero

6 votes

Distance of two points in $\mathbb{R}^N$ $\leq$ length of curve

5 votes
Accepted

Prove that a function is bijective and show that G is a group

5 votes
Accepted

Is there an easier way to calculate the partial derivative?

5 votes

$1/(1-x)$ series: dividing by zero?

5 votes

Another definition of normal operator

4 votes
Accepted

Is $\sin ^{2}\left ( x-y \right )$ metric space?

4 votes
Accepted

Find a solution for a differential equation, assume that $y(x)=ax^2+bx+c$

4 votes
Accepted

Showing $f\in C^{\infty}$ and calculating $Df(x)$

3 votes
Accepted

Distance between line and plane in $\mathbb{R}^4$

3 votes
Accepted

Is this projection linear? $\mathbb{R}[X]\to\mathbb{R}[X], f\mapsto f' $

3 votes
Accepted

Solution of this Ordinary Differential Equation

3 votes

Let $\{a_n\}_{n \in \Bbb N}$ be convergent. Prove/Disprove: $\lim\limits_{n\to\infty}$ $|a_n - a_{2n}| = 0$

3 votes
Accepted

How to find this transformation matrix with respect to the standard basis?

3 votes

Proof about inner product space $\vert \langle x,y\rangle \vert=\Vert x \Vert\Vert y \Vert$

3 votes
Accepted

Scalar Product on $\mathbb{R}^3$

3 votes
Accepted

Understanding the proof of a theorem using Hahn-Banach Theorem.

3 votes

Does convergence of the absolute value of a sequence imply convergence of the sequence?

3 votes
Accepted

Is $f - 3I$ an isomorphism if $f$ is orthogonal?

3 votes
Accepted

How do we denote the $0$ vector in a Quotient Space $V /W$?

3 votes
Accepted

Show that triple product is invariant under rotations

2 votes
Accepted

For what values of a parameter is a given vector an eigenvector of a given matrix?

2 votes

Absolute Value of Complex Function to a Power

2 votes
Accepted

How accurate is the solution to this surd question.

2 votes
Accepted

Prove that x is an eigenvector of C, and find the eigenvalue of C

2 votes
Accepted

Determining the eigenvalues of a $4×4$ block diagonal matrix.

2 votes
Accepted

Proving $E_\lambda(T)=E_{\lambda^{-1}}(T^{-1})$

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