Voyska
Reputation
Top tag
Next privilege 10,000 Rep.
Access moderator tools
 16h comment How do I express logical connectives with Nand? @MauroALLEGRANZA You can use $\uparrow, \rightarrow, \downarrow, \leftarrow, \triangle, \times ,\bigcirc, \times, \square, \triangle$ to attack with Akuma's combo on Street Fighter $V$. Jul28 comment What's the meaning of the $R(f(x),g(x))$ in $\int R(f(x),g(x))?$ See Apostol's: Calculus or Courant/Fritz': Introduction to Calculus and Analysis. Jul27 comment What would be interesting maps to use on that Eudoxus reals? @lulu Yes. But I'm not sure of what $f$ would be useful for this construction of the Eudoxus reals. I'm reading this but it doesn't ring a bell. Jul27 comment What would be interesting maps to use on that Eudoxus reals? @lulu I don't get it. If I take $f(x)=mx+b$, I'd have: $$f(x+y)-f(x)-f(y)=m(x+y)+b-(mx+b)-(my+b)=-b$$ That doesn't seems meaningful. Jul21 comment Minor mistake computing $\int \frac{1}{x^3+2x^2-3x} \; dx$? Oh, thanks. When I expanded it in the board, I (wrongly) found $-3c$. Now I expanded it with Mathematica and obtained the right result but didn't pay attention. Jul17 comment Why $\frac{1}{9}$ becomes $\frac{1}{3}$ in $\frac{1}{3} \int \frac{1}{s^2+1} \, ds$? Okay. But is it wrong to use the product rule? Or it's just more practical to use this rule? Jul17 comment Why $\frac{1}{9}$ becomes $\frac{1}{3}$ in $\frac{1}{3} \int \frac{1}{s^2+1} \, ds$? I've added an edit. Could you take a look at it? Jul17 comment Why $\frac{1}{9}$ becomes $\frac{1}{3}$ in $\frac{1}{3} \int \frac{1}{s^2+1} \, ds$? I don't understand why I have $ds=\cfrac{1}{3} du$. I don't understand how does $ds$ relates do $du$. Jul13 comment Statistics books with motivation and historical tidbits about the development of the concepts? @MichaelHardy Yes. And I'm looking exactly to the mathematical motivation for them. I'm curious to know exactly what made them develop the concept (be it "mathematical" or not). I marked "mathematical" because sometimes in the development of mathematics, things were not really mathematically justified, such as Leibniz infinitesimals. Jul6 comment Is it a good practice to write this integral in this form? @JohnMa I'm supposing I don't know it for a while. But I'll compute it a little later. Do you think this presents a big problem? Jul3 comment Reference Request: Regge Symmetry “Angle-Edge” Duality I believe Bob Marley is a feasible reference to what you're looking for. Jul3 comment How to get rid of the term with $xy$? One silly doubt: In the book I'm reading, it says about eliminating the linear terms, in another place I've read, it seems that the objective is to eliminate the term with $xy$. Are they equivalent? There is also another book I have that says that the objective seems to be to write the conic in the form $ax^2+bxy+cy^2$. I'm a little confused. Jul3 comment How to get rid of the term with $xy$? I need to do a change of variable such that $xy=0$, right? Jul3 comment How to get rid of the term with $xy$? @r9m What's the difference of them? I know that this matrix form is associated (can be expanded) to a quadratic form. But I'm not sure what your matrix does. Jul3 comment How to get rid of the term with $xy$? @r9m There are two matrixes. This one you mentioned and: $$\begin{pmatrix} {x}&{y}&{1} \end{pmatrix}\begin{pmatrix} {a}&{b/2}&{d/2}\\ {b/2}&{c}&{e/2}\\ {d/2}&{e/2}&{f} \end{pmatrix}\begin{pmatrix} {x}\\ {y}\\ {z} \end{pmatrix}$$ Jul3 comment Should the expanded expression of a quadratic form be equals to It's original expression? @RoryDaulton That is also viable. But In my mind, they didn't seem valid for operations in equations. But I jsut checked Apostol's book and saw that they are indeed appropriate. Thanks for pointing it out. Jul3 comment What is the $1469^\text{th}$ derivative of $x^{532}-5x^{37}-4$? @DavidRicherby I know. I just said it to enhance his mathematical culture. Jul2 comment Special Products of Transpositions @Blue You could (should?) have asked it on Math Overflow. As it seems pretty exploratory: "Have these "special permutations" been studied in the literature?" - I guess they'll not close the question. Jul2 comment What is the $1469^\text{th}$ derivative of $x^{532}-5x^{37}-4$? It might be good for you to know the existence of Faá di Bruno's generalization of the chain rule to higher derivatives. Jul1 comment When should I shift $a$ and $b$ in $\cfrac{x^2}{a^2}+\cfrac{y^2}{b^2}=1$? @OfirSchnabel Oh. Then I probably made some mistake in the previous computations. Gonna try it now.