bio | website | |
---|---|---|
location | Reykjavik, Iceland | |
age | 38 | |
visits | member for | 4 years, 10 months |
seen | Apr 12 '10 at 12:43 | |
stats | profile views | 130 |
Post-doctoral researcher at Reykjavik University
Mar 8 |
awarded | Good Answer |
Feb 10 |
awarded | Enthusiast |
Oct 24 |
awarded | Nice Answer |
Oct 23 |
answered | Most helpful math resources on the web |
Oct 23 |
comment |
Dyck paths on rectangles
No? Take the rectangle, rotate it 45 degrees clockwise so that the diagonal becomes the x-axis, then reflect it in the x-axis. |
Oct 23 |
comment |
Placing checkers with some restrictions
Ah, yes. It can probably be fixed, somehow. |
Oct 23 |
answered | Dyck paths on rectangles |
Oct 23 |
awarded | Editor |
Oct 23 |
revised |
Placing checkers with some restrictions
Added a sketch of the bijection |
Oct 22 |
answered | Placing checkers with some restrictions |
Oct 22 |
answered | why is it so cool to square numbers? (in terms of finding the standard deviation) |
Oct 22 |
comment |
why is it so cool to square numbers? (in terms of finding the standard deviation)
Ilya seems to have confused variance and standard deviation. The variance of the sum of independent random variables is the sum of the variances: Var(X+Y)=Var(X)+Var(Y) so StdDev(X+Y)=sqrt(Var(X)+Var(Y)), which in general is not equal to StdDev(X)+StdDev(Y) |
Oct 21 |
awarded | Supporter |
Oct 21 |
comment |
Pairs of shortest paths
See David Speyer's answer, who was actually worked through the details! |
Oct 21 |
awarded | Teacher |
Oct 21 |
answered | Pairs of shortest paths |