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 Apr 7 comment Generic term for results of applying mathematical transformation to a value Since this is for a very small audience, it might be best to ask them directly, on math.SE Mar 2 comment What does strength refer to in mathematics? When profs use this word, it sounds very informal and vague because it appeals to intuition about better and worse without specifying in what way (sometimes strong sounds good, sometimes not). Also, 'strength' is not about the content but about the reasoning. But it can be given a formal treatment in elementary logic as strength = fewer assumptions or more consequences, or "X is stronger than Y" = "X implies Y". Back to the vague idea, X does more than Y, often with less. Feb 24 comment Are proofs by contradiction really logical? @nocomprende also, philosophy is just talk. Real logic is done in mathematics. ducks and runs Feb 24 comment Are proofs by contradiction really logical? @nocomprende just like with geometries and axioms (Euclidean geometry has the parallel postulate, hyperbolic says more than one allowed through a point parallel to a line, etc), logic itself has axioms. And you can allow some axioms or not. Allowing excluded middle, you get classical logic. Without it (that is, not enforcing it absolutely always), gets more constructive logics (you can't prove as much but what you can prove is usually gets you an example). Feb 24 comment Are proofs by contradiction really logical? Twitter style answer (but too long): if you make a proof going from the hypothesis to a conclusion that is false, something must have been wrong along the way. If you did everything right along the way, the error must have been the assumption at the start Jan 3 comment Reference to an atlas of curves and surfaces? @bubba oh, yes, I get that. The point of asking for an atlas is to collect all the equations and their properties in one place so that one might more easily do as you suggest. Jan 3 comment Reference to an atlas of curves and surfaces? @bubba sure but from where? Where do you get the 3D printer designs? Dec 28 comment Factorial and exponential dual identities Nice! Can you relate this theorem to the ordinary and exponential generating function in my comments to the OP: $g(x)=\int_0^{\infty} e^{−u}G(xu) du$? Also, can you give any meaning/interpretation to the master theorem here? Dec 11 comment Determining the number of zeros in the upper half plane If only there were an easy way to visualize complex functions. It's basically like having to see 4-dimensions, where 2 are the independent variable and another 2 dependent. Sadly hand graphing calculators won't do it. (computer algebra packages might help). I'm only suggesting this as visualization, not analytic solution for the exact answers. Nov 18 comment Combinatorics Identity about Catalan numbers. Do you want an algebraic proof or a combinatorial one? Nov 16 comment Assumptions needed for proof of the Pythagorean Theorem from examples @DamkerngT The proof of PT via Heron's formula is an interesting alternate proof by nontraditional means. And I am looking for an alternate proof of PT, but very different. I know it seems like a strange thing to look for, a proof using finite examples, because most proofs try to avoid instances. Nov 15 comment Determinant tridiagonal matrix How did you get the linear recurrence? (in case the values on the diagonals change) Nov 15 comment Where to learn how numbers work? @A.P. Thanks for the edits. Yes I was aware of the reading difficulty. I don't know how a screen reader really works, but at least the LaTeX itself is fairly readable (which is close to how I would write it without screen formatting without LaTeX. Nov 15 comment Where to learn how numbers work? Are you asking about fibonacci or exponentiation or addition or what? fib is just defined that way, there's no justification to be had. The single algorithm you gave for exponentiation by repeated squaring is not obvious but does have a justification. The way you asked the question is too broad "How does it all work?" You need to specify for us to have a reasonable chance to answer. Nov 15 comment Where to learn how numbers work? You don't know why what is correct? Nov 15 comment Assumptions needed for proof of the Pythagorean Theorem from examples ... In other words, I am not looking for a simple proof of PT, rather a constrained proof, one where you use instances of PT and some other facts (this is what I'm looking for). Nov 15 comment Assumptions needed for proof of the Pythagorean Theorem from examples @robjohn As you note there are many proofs of PT. Some of them rely on different things, things that are independent, but eventually lead to the same thing, PT. I am trying to explore a different path. Yes, I realize (as I have noted in comments) that some of the tiling proofs of the individual items are extremely close to a full general proof of PT. But frankly one of the PT proofs are extremely close to the more general 'the sum of areas on similar shapes on the legs equals the area of a similar shape on the hypotenuse' but intellectually it is a difficult leap to discover. Nov 13 comment Generating Pythagorean Triples from Others via Dissections Forget dissection for the moment, do you have any visualization for the matrix multiplication (relevant to the geometry of a triangle)? Nov 12 comment Solve a matrix product without computing the inverse Do you need to do this by hand, or do you need an algorithm, or do you want to prove a statement about how to do this? (sure the last two are similar but the last one is more work) Nov 10 comment Assumptions needed for proof of the Pythagorean Theorem from examples Also, would take 3 instances if the form were as given in my comment and edited question. Is it that simple? Also, is there any quick intuition that would make someone guess that the relation is some combination of areas?