hardmath

Knoxville, TN

uclue.com

Age: 62

Enjoys programming in Prolog.

Richard O'Keefe: "Prolog is an efficient programming language because it is a very stupid theorem prover."

When I cross the street, I look both ways: up and dn.

13h
comment Factorization of huge integer
Curiously $9623$ is itself the smallest of three prime factors of $2^{283}-1$.
13h
comment Factorization of huge integer
@YuvalFilmus: The fact you noted depends on the exponent $n$ being prime.
13h
comment Factorization of huge integer
While it will certainly help to factor the Mersenne candidates $2^{9623} - 1$ and $2^{22271} - 1$, that will not give all factors of $2^{9623\cdot 22271} - 1$, and it might not even give the smallest prime factor.
1d
comment What's the equation for possible 2 step sequences on a 3x3 grid?
It might be you are thinking of a random walk on a grid? If you know the possible one-step sequences, then you can build up from that the 2-step and 3-step sequences, but you've not given the Reader a starting point.
1d
comment What are some interesting project ideas related to game theory?
This Question is not a good fit for Math.SE as currently phrased. What constitutes "interesting project ideas related to game theory" seems not only subjective but overly broad. Certainly many two-player recreational "perfect information" games have mathematical roots, but by project you seem to have in mind "coding... using MATLAB", so it isn't even a mathematical investigation per se that you seem to be contemplating.
1d
comment how to answer with a format in stackoverflow
Comments are fairly short in length, and also intended for clarification of Questions and Answers, so that a Comment may well be deleted by its author once the purpose is served. Anything that deserves elaborate formatting should be included ultimately in a Question or Answer.
2d
answered Non-linear system vs minimisation problem
2d
comment Orthogonality and Kernel
That said, you really need to include such pertinent details in your Question statement.
2d
comment Orthogonality and Kernel
Note that $W$ is the column space of $A$. Thus being orthogonal to $W$ is equivalent to being in the null space of $A^T$ since the row space of $A^T$ is simply the transposed image of $W$, to make the matrix multiplication $A^T (\mathbf{b} - \text{proj}_W \mathbf{b}) = 0$ work out.
2d
reviewed Edit Orthogonality and Kernel
2d
revised Orthogonality and Kernel
math formatting
2d
reviewed Reopen Non-linear system vs minimisation problem
2d
comment Non-linear system vs minimisation problem
@KAT: I appreciate your effort to narrow the scope of this Question, and I will accordingly vote to reopen. However it remains rather broad, and the only Answer I would expect to muster would deal only with some big picture aspects of the Question. It might find a more thoughtful response at the SciComp.SE Community, if you are not already familiar with it.
2d
comment Showing $\lim_{(x,y) \to (0,0)} \sin (xy) / xy = 1$
Hint: Use a small neighborhood of $(0,0)$ to show that as $(x,y)$ tends to $(0,0)$, $xy$ tends to zero.
2d
comment Constructing a set that contains at most one point on vertical and horizontal
I think you have misunderstood the assumptions. Saying $A$ contains "at most one point on the horizontal and vertical lines" does not mean it contains a point on every horizontal and vertical line.
2d
comment What is the connection between random variables and time series?
Hi, arj, and welcome to Math.SE! You've picked a challenging first Question to tackle. However a terse note, giving a search term "ergodic process" for the Reader to pursue, is not quite the well-curated Answer that StackExchange is trying to build its reputation on. Please expand your Answer, and if necessary or expeditious, summarize the fuller details that can be found elsewhere at a specific website.
2d
reviewed Close Theory automata. Proof.
2d
reviewed Leave Open $f(X)$ is uncountable and hence $X$ is uncountable.
2d
reviewed Close Statistics probability question
2d
reviewed Edit Does every subset of a metric space have an open cover?
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