123,729 reputation
8117240
bio website von-eitzen.de/math/tntrep.xml
location Bonn, Germany
age 49
visits member for 2 years, 3 months
seen 9 hours ago

I did study math and had a knack for it, but I am sooo out of that business now ...


Feb
5
revised Show that if $\{X_n\}$ is bounded above and no cluster points then $\lim X_n=-\infty$
added 16 characters in body; edited title
Feb
5
comment is there a problem in the answer? finiding an angle
@daveo How is the sum of angles in $BAD$ more than $180^\circ$? Make a sketch. You will find that $\angle BAC=109.47^\circ$ and $\angle DAB=70.53^\circ$.
Feb
5
answered is there a problem in the answer? finiding an angle
Feb
5
comment Difference between a tree and spanning tree?!
To complete the list, you might add a spanning subgraph that is not a tree - for example the cyclic graph formed by the outer edges
Feb
4
answered $\liminf _{n\to\infty}(u_n+v_n)$ when just $u_n$ is known to converge?
Feb
4
reviewed Reviewed Complete reducibility of a field extension of an lie algebra representation
Feb
4
reviewed Close Find the nature of $f'(x)$
Feb
4
comment Let $(X, d)$ be a metric space. Does a result proved for the metric $d$ apply to every metric $d^{'}$ on $X$?
Note that the property "bounded" depends on $d$. In fact you can replace a metry $d(x,y)$ with $\frac{d(x,y)}{1+d(x,y)}$, which gives the same topology but makes everything bounded.
Feb
4
revised A Special Type Of Guess The Number Game
added 384 characters in body
Feb
4
answered A Special Type Of Guess The Number Game
Feb
4
answered How is a “computer variable” defined mathematically?
Feb
4
revised Find all finite set S such that any $a, b, c \in S$, $ab + bc + ca \in S$
added 865 characters in body
Feb
4
answered Number theory problem assignment
Feb
4
answered Metric inducing a topology
Feb
4
answered A sequence with 2 accumulation points which, intuitively, converges to 0
Feb
4
answered Distribute a population size based on fractions using random number generator drand48()
Feb
4
answered Find all finite set S such that any $a, b, c \in S$, $ab + bc + ca \in S$
Feb
4
awarded  elementary-number-theory
Feb
3
answered Convergence over the $p$-adic numbers
Feb
3
answered How to calculate the points of the triangles making up an Octahedron?