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visits member for 3 years, 3 months
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8h
comment How can I prove that $\: \operatorname{Pr}[Y=0] \leq (\operatorname{E}[Y^2] - (\operatorname{E}[Y])^2)/\operatorname{E}[Y^2] \:$?
@Did : $\:$ Did I do so here? $\;\;\;\;$
9h
revised How can I prove that $\: \operatorname{Pr}[Y=0] \leq (\operatorname{E}[Y^2] - (\operatorname{E}[Y])^2)/\operatorname{E}[Y^2] \:$?
TeXified and fixed grammar
9h
comment Prove $f(x) = \frac{1}{x^2}$ is uniformly continuous on $[1, \infty]$
However, the metric $\;\; \langle x,\hspace{-0.03 in}y\rangle \: \mapsto \: |\hspace{.02 in}x\hspace{-0.04 in}-\hspace{-0.04 in}y\hspace{.02 in}| \;\;$ does not induce the usual topology on $\:[1,\hspace{-0.04 in}\scriptsize+\normalsize \infty \hspace{-0.02 in}]\;$. $\hspace{1.34 in}$
2d
comment Assume that the square matrix A has an eigenvalue of 0. Is A invertible? Why or why not?
The 1-by-1 matrix over $\mathbb{R}\lbrack x\rbrack$ whose entry is $x$, and the $\mathbb{N}$-by-$\mathbb{N}$ matrix with ones on the subdiagonal $\hspace{.45 in}$ and zeros everywhere else, are both non-invertible matrices that do not have 0 as an eigenvalue. $\hspace{.66 in}$
Apr
13
revised Mean Value Theorem: Continuous and Differential
replaced "differential" with "differentiable"
Apr
6
comment Non-empty intersection between a compact and an unbounded connected subset of $\mathbb{R}^d$
What is $P$? $\;$
Apr
5
comment Is there a way to denote the calculation $1+2+3+\dots+n$?
whortening $\mapsto$ shortening $\:$ ? $\;\;\;\;$
Mar
31
comment Why axiom with negation is required in propositional logic?
What is "[]"? $\;$
Mar
31
asked In what topological abelian groups does convergence to zero imply summability?
Mar
29
comment Find the regularized sum $\frac{1}{\ln(2)}+\frac{1}{\ln(3)}+\frac{1}{\ln(4)}+…$
@recursiverecursion : $\:$ Mike used LaTeX. $\;\;\;\;$
Mar
28
comment How to explain the power of PA to non-logicians
@Martin : $\:$ If I remember right, PA should also prove all instances of "Every strategy at the $\hspace{.92 in}$ $k$-th level of the arithmetical hierarchy will kill this hydra.". $\;\;\;\;$
Mar
28
comment How to explain the power of PA to non-logicians
Note that one needs to apply "Rosser's trick" to get the theorem mentioned in this answer. $\hspace{1.04 in}$
Mar
24
comment Can the natural number have an uncountable set of subsets?
Just let each $X_i$ be $\mathbb{N}$. $\;$
Mar
24
accepted Strictly convex norms instead of inner products on the tangent spaces
Mar
23
comment Strictly convex norms instead of inner products on the tangent spaces
(I started wondering about this while I was taking a class on Riemannian manifolds.) $\hspace{1.43 in}$
Mar
23
asked Strictly convex norms instead of inner products on the tangent spaces
Mar
23
accepted Does one of these conditions for norms follow from the other?
Mar
21
asked Does one of these conditions for norms follow from the other?
Mar
20
comment Find the center of the symmetry group Sn.
(Note that n=2 will be a special case.) $\;$
Mar
18
comment Calculating set partitions with minimum variance
en.wikipedia.org/wiki/… $\;$