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seen Jun 24 at 23:22

Feb
7
answered Expected value of the product of functions of two independent random variables
Feb
5
comment $\lim_{n\to\infty} \sqrt[n]n = 1$
@dkuper when I took that class we introduced the exponential function later, so we couldn't use that argument. It is indeed even simpler though.
Feb
5
revised $\lim_{n\to\infty} \sqrt[n]n = 1$
added 215 characters in body
Feb
5
awarded  Yearling
Feb
5
answered Give me a example of a function Lebesgue Integrable over [a,b] that is not bounded in any subinterval of [a,b]
Feb
4
answered $\lim_{n\to\infty} \sqrt[n]n = 1$
Feb
4
comment Is it acceptable to solve hypothetical statements in Linear Algebra using actual numbers?
To this I'd add that trying to find counterexamples to true statements can be a good first step towards understanding how to prove them.
May
20
comment Finite difference method stability
The extra term doesn't go to zero, because the solution of the PDE doesn't necessarily go to zero as $n\to\infty$ if there's a forcing term. However, if you have some numerical solution $U$ with a right-hand side $f^i$ and another solution $V$ with the right-hand $f^i+\delta f^i$, then $\|V^n-U^n\| \le \|B^n\|\|U^0-V^0\|+k\sum_{i=1}^n\|B^{n-i}\|\|\delta f^i\|$. Knowing that the discretization is consistent, you can use this fact to show it's convergent as $n\to\infty$ and $k\to 0$, provided $kn \to$ some finite number $T$.
May
17
revised Finite difference method stability
adding more info a propos of an additional comment by OP
May
17
awarded  Constituent
May
17
awarded  Caucus
May
17
answered Finite difference method stability
May
17
comment Finite difference method stability
Perhaps this is better migrated to the computational science stack exchange?
May
17
awarded  Critic
May
15
comment Is restriction of compact operator always compact?
Bingo! Also: that sequence isn't bounded in the graph norm, so you can't use it to say that the operator isn't closed. @julien: Thanks for pointing that out -- the upshot is that the set of compact operators is closed in the strong operator topology, right?
May
13
answered Is restriction of compact operator always compact?
May
8
answered Need help in question for conditional expectation
May
2
comment Functions differentiable on {$z \in \mathbb{C}: 0 < |z| < 1$}
The square root function has a branch cut; it's not differentiable in the disk, you have to remove a line along some axis, usually the negative real line.
Apr
18
comment For any graph G, How do I find the algorithm that returns the permutation of vertices with minimum bandwidth?
(a) I'm exaggerating yes, but it's still O(n!) right? (b) I stand corrected! I didn't know about interval graphs but the maximal clique ordering property would make it much easier to order them nicely. The "stupid example" I'm thinking of is the matrix discretizing a differential operator in 1D.
Apr
18
answered For any graph G, How do I find the algorithm that returns the permutation of vertices with minimum bandwidth?