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bio website google.com
location New York, NY
age 94
visits member for 2 years, 8 months
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I like fish! And agonizing over solving the Finite Sub-Cuddling hypothesis!

The chameleon, incidentally, says "Maaaaaaaaaaaaaaaaattthh!"


Aug
15
comment Matrix partwise multiplication
I don't think there's going to a be a particularly useful characterization of the solution space. Note that your sum-product doesn't correspond to any matrix operation I'm familiar with - neither matrix product, nor outer product, nor Kronecker Product (some similarlity there). For any fixed $M_{i, j}$, you can find an $F_{i, j}$ to make their product $A_i$; and arguing similarly, use two other row entries to make them equal in absolute value, but of opposite sign - you get typically an infinite solution space. That said, maybe it's a matrix operation I'm unfamiliar with.
Aug
15
reviewed Reopen Example of a group in which the equation $x^2=e$ has more than two solutions
Aug
15
reviewed Leave Closed Proof correctness problem
Aug
15
reviewed Close Riemann Integrability over [1,5]
Aug
15
reviewed Close Where did $-4x$ come from?
Aug
15
reviewed Leave Open What do you call a matrix where the rows sum to zero and the columns sum to zero?
Aug
12
comment Help showing that every walk of length $k$ from $x$ to $y$ in a graph is a path.
Depends in course definitions, to an extent. But you probably will have: a path is a walk with no cycles; distance is the shortest path between two vertices. So if the walk has length k, and had a cycle, you can cut that cycle out and get a path from the walk which - given cycle length > 0 - makes the length of the path < k. Contradiction to distance k.
Aug
9
reviewed Leave Open Calculus problem with a triple equation
Aug
9
reviewed No Action Needed Calculus problem with a triple equation
Aug
9
reviewed No Action Needed Prove that the sequence with $T(0)=1$ and $T(n) = 1 + \sum_{j=0}^{n-1}T(j)$ is given by $T(n)=2^n$
Aug
9
reviewed Close Plis, What is the orthogonality conditions for associated legendre polynomials with both two different indexes
Aug
9
comment Plis, What is the orthogonality conditions for associated legendre polynomials with both two different indexes
This question appears to be off-topic because it is about cutesy talk like "Plis" makes me extremely uncomfortable.
Aug
1
revised Let $A \subset \mathbb{R}$ be connected and $f:A\to \mathbb{R}$ be continuous. Show $f(A)$ is connnected
edited tags
Aug
1
revised A silly problem on equivalent statements of linear dependence
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Aug
1
revised Simple subgroup proof, would love some advice
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Aug
1
revised If G is a finite group with an even number of elements, then binary product of two distinct elements is identity.
edited tags
Jul
25
revised How to show $\psi^*(x,-t)$ is also solution of the Schrodinger equation
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Jul
25
revised Solve the given differential equation by using Green's function method
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Jul
24
comment Binomial dependent on a Poisson
If you'd like to learn a lot of the tricks that, if you don't know them, seem like magic, grab this book from your library. (When I was in grad school, I wish I had earlier)
Jul
24
comment The Goblin Game
I am fairly sure this game doesn't have a solution that helps you. It reminds me of an experiment by Selten I participated in: a repeated game in which in each round each participant writes down a number from 1-20, and whoever is closest to half the numbers' average wins that round. The averages. maybe not surprisingly, slowly approached zero; and in the last round one sociology student proudly told me he figured out that using 20 would maximize his chances! (Having observed winning numbers of about 7, 5, 3 before). Even assuming you'd find a NE, your friends are unlikely to play by it.