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An amateur general topology researcher.


Apr
21
revised Mapping unit sphere to ellipsoid
added 9 characters in body
Apr
21
asked Mapping unit sphere to ellipsoid
Apr
21
comment Matrixes and modulo of a vector
What if we replace $\lvert Mv\rvert$ with $v^T M v$?
Apr
21
comment Matrixes and modulo of a vector
@1950RobertLewis: $v$ is a variable taking arbitrary vector values
Apr
21
comment Matrixes and modulo of a vector
Hm, it isn't injective: Take matrix $M'=-M$. But can $\lvert Mv \rvert$ be equal to $\lvert M'v \rvert$ if $M\ne M'$ and $M\ne -M'$?
Apr
21
revised Matrixes and modulo of a vector
edited body
Apr
21
asked Matrixes and modulo of a vector
Apr
18
accepted A trigonometric equality
Apr
18
comment A trigonometric equality
The last implication seems wrong. And it is not quite clear how the answer follows from the last equality
Apr
18
comment A trigonometric equality
"simplify cotan arccos(y/sqrt(y^2+x))" at Wolfram Alpha suggests that my equality is true
Apr
18
asked A trigonometric equality
Apr
17
asked An error in Wikipedia? (trigonometry)
Apr
15
accepted Splitting Frechet filter into two proper filters
Apr
15
asked Splitting Frechet filter into two proper filters
Apr
15
asked Going down from filters to sets for specific relations
Apr
14
comment Certain constructs on filters and on principal filters
Now after some investigations, I strongly suspect that both conjectures are false. However I do not know a counterexample.
Apr
14
revised Certain constructs on filters and on principal filters
added 173 characters in body
Apr
14
revised Certain constructs on filters and on principal filters
added 11 characters in body
Apr
14
revised Certain constructs on filters and on principal filters
added 11 characters in body
Apr
14
revised Certain constructs on filters and on principal filters
added 7 characters in body