365 reputation
128
bio website jlazovskis.com
location Waterloo, Canada
age
visits member for 1 year, 11 months
seen Apr 12 at 4:45

Aug
31
comment Regional Mathematics Olympiad(RMO-India) Geometry Problem
Watch your assertions there, guy. I have zilch idea of what level your competition is at; there are competitions where this type of language is used to mask a simple problem, i.e. one where any specific situation simplifies to the general case.
Aug
31
comment Regional Mathematics Olympiad(RMO-India) Geometry Problem
My bad, I'm not familiar with the RMO-India question setup. Questions posed in this way in competitions I've gone to can be solved in this way.
Aug
31
answered Regional Mathematics Olympiad(RMO-India) Geometry Problem
May
27
comment What is the metric tensor on the n-sphere (hypersphere)?
Great, thanks for the step-by-step explanation. Although what you've written is fairly clear, you can make it clearer by using the TeX environment, with the $ delimiters, like instead of g'rϕk, write $g'_{r\phi_k}$, which comes out as $g'_{r\phi_k}$.
May
27
accepted What is the metric tensor on the n-sphere (hypersphere)?
May
25
asked What is the metric tensor on the n-sphere (hypersphere)?
May
11
awarded  Tumbleweed
May
9
accepted Spherical geometry - relating angles of lunes and segments of great circles
May
9
comment Spherical geometry - relating angles of lunes and segments of great circles
@robjohn Indeed! Your answer is correct.
May
9
comment Spherical geometry - relating angles of lunes and segments of great circles
@robjohn Regarding your answer below, the side $\varphi$ should be $\varphi r$, and $\theta/2$ should be $\theta r/2$. I am assuming (though not 100% sure) that will change your relation accordingly. Is that correct?
May
9
comment Spherical geometry - relating angles of lunes and segments of great circles
@robjohn Yes, that's a better description
May
9
revised Spherical geometry - relating angles of lunes and segments of great circles
added more clarification about geodesic
May
9
awarded  Editor
May
9
revised Spherical geometry - relating angles of lunes and segments of great circles
added clarification
May
9
asked Spherical geometry - relating angles of lunes and segments of great circles
May
4
asked Relation between triangle and its circumscribed circle, on the surface of a sphere. Generalizations to higher dimensions.
May
2
comment An explicit bijection between $R^n$ and $S^n\setminus \{$point$\}$
The reason why I wanted $n$-spherical coordinates is to see where an $n$-simplex on the surface of the $n$-sphere would map to in $R^n$, and I know how to express the $n$-simplex on $S^n$ in $n$-spherical coordinates. But now I'm thinking stereographic projection might be just as easy, if I center the simplex at the south pole of the sphere (the pole opposite from which the projection is done). Hmmm.
May
2
asked An explicit bijection between $R^n$ and $S^n\setminus \{$point$\}$
May
1
comment Curvature (Gaussian) of a hypersphere
@BabakS.I see now - my question is wrong, as Gauss curvature applies to 2-dimensional surfaces, and its higher-dimensional analog is sectional curvature, which is indeed $1/r^2$ at every point.
May
1
awarded  Commentator