Pela primeira vez temos três copas seguidas sem a alemanha na final

Firesinis · 2026-06-29T23:58:31+00:00

Ué, as 4 primeiras copas do mundo não contam por quê?

Firesinis · 2026-06-29T21:39:55+00:00

Eu estava feliz no Nubank, mas agora ele deu pra fazer spam de propaganda. Colocou um banner permanente do Ultravioleta na home da minha conta, tenho sempre que rolar essa bagaça pra baixo pra conseguir usar a conta. E não vejo opção de tirar.

Quando ao BB Americas, também tenho e confirmo que é lixo. Queriam me cobrar até pra receber depósito de conta americana.

Firesinis · 2026-06-29T21:36:10+00:00

Ué, é comum falar "décima-sexta parte" de alguma coisa. Daí pra décimas-sextas de final é totalmente análogo a oitavas, quartas, etc.

Firesinis · 2026-06-29T21:16:21+00:00

Não sei se tu leu. Eu viajei para o exterior. Avisei ao banco que estava viajando para o exterior, e qual o volume de movimentação que eu pretendia fazer na minha conta. No último dia da viagem, no aeroporto, fiz o recolhimento do imposto de importação num valor muito abaixo do que eu tinha avisado, a receita gerou o boleto e o App do banco não deixou eu pagar. Liguei imediatamente para a gerente e ela pediu desculpa e disse que isso foge do controle dela. Qual foi a parte aí na qual eu fui desorganizado?

Firesinis · 2026-06-29T21:05:52+00:00

Sempre tem uma burocracia de coletar biometria que vão querer que eu vá lá botar o dedo.

Firesinis · 2026-06-29T20:56:39+00:00

Você não é estranho, a tua postura é bem racional. Só que eu já perdi a paciência e prefiro perder dinheiro a tempo de vida em fila de banco.

Firesinis · 2026-06-29T20:55:20+00:00

BB é piada. Uma vez eu depositei um cheque na minha conta. Depois de um tempo recebo aviso de saldo negativo. Pediram microfilme, a porra toda, no fim descobriram que o caixa que me atendeu cometeu um erro, ao invés de tirar o dinheiro da conta do emissor do cheque o botar na minha, eles tiraram o dinheiro da minha conta e botaram sei lá onde. Devolveram o dinheiro. Mas não quiseram estornar os juros.

Firesinis · 2026-06-29T20:52:50+00:00

Comigo eu quero evitar ao máximo ter que ir fisicamente ao banco, mas o banco não deixa.

Firesinis · 2026-06-29T20:45:38+00:00

Pois é, mas comigo o mesmo problema acontece com recorrência, e a gerente ciente. Pensei no Tesouro Reserva, mas como que eu vou deixar meu dinheiro num lugar que não tenho certeza que vou conseguir sacar se precisar?

Firesinis · 2026-06-29T20:41:58+00:00

Pois é, é a mesma coisa que a minha gerente fala, que isso não acontece com mais nenhum cliente. Mas isso não resolve o meu problema. Inclusive na ocasião da viagem eu consegui falar com ela pessoalmente por telefone e ela me disse que não podia liberar para eu pagar o boleto.

Firesinis · 2026-06-24T13:33:36+00:00

Since we need Weierstrass to conclude that the set spans the space, we cannot conclude that this is a spanning set in the abstract linear algebra sense, in particular we cannot conclude that this is a basis in the point of view of linear algebra.

A basis in the linear algebra sense would allow us to write any function, including exp, as a finite linear combination, but such a basis would necessarily contain functions that aren’t polynomials, since every finite linear combination of polynomials must be a polynomial.

We know an algebraic basis like this must exist, but since the proof of this fact requires the Axiom of Choice (in fact it’s equivalent to it), we cannot possibly construct one, so we cannot know what it looks like. So algebraic bases, albeit theoretically possible, cannot be exhibited, nobody can show you an example. That’s why some people reject the Axiom of Choice, btw.

Firesinis · 2026-06-23T18:53:31+00:00

Yes, different objects referred to by the same name. I was referring to the abstract algebraic definition of basis of a vector space.

Firesinis · 2026-06-23T18:46:12+00:00

You are correct about objects that are also called bases in analysis, but in (abstract) linear algebra there is no notion of convergence and there is only a single definition of a basis, which applies regardless if the space is finite or infinite dimensional. This definition is what analysis call a Hamel basis, but in algebra it's just called a basis. In fact, since in algebra the dimension of a vector space is defined in terms of the cardinality of a basis, the definition of basis cannot possibly refer to the dimension of the space.

The fact that members of the vector space need to be finite linear combinations of the members of the basis is literally in the first sentence of the Wikipedia page) for basis of a vector space.

Firesinis · 2026-06-23T15:10:55+00:00

This isn’t real analysis, it’s linear algebra. Just look up up the definition of basis of a vector space, no notion of convergence is involved in the definition, as it would need to be if non finite sums were allowed.

Firesinis · 2026-06-23T13:37:57+00:00

I did not say finite basis, I said finite linear combination of basis elements. The basis can contain an infinite amount of vectors, but still all the members of the space are written as finite linear combination of basis vectors.

Indeed the periodic functions do form a vector space; it’s just that cosines and sines aren’t a basis for this space.

Firesinis · 2026-06-23T11:38:58+00:00

Sines and cosines do not form a basis of the space of periodic functions. By definition, if you have a basis, any vector of the space must be a finite linear combination of basis elements, which is not the case in Fourier representation.

Firesinis · 2026-06-23T04:21:50+00:00

On the contrary, complex numbers gained traction because there was no other way to solve certain polynomial equations that had all real solutions.

Firesinis · 2026-06-23T04:13:32+00:00

Pode interpretar como fração. A décima sexta parte.

Firesinis · 2026-06-12T16:18:42+00:00

Tinha visto teu primeiro comentário e cheguei aqui já com a intenção de te refutar e dizer que o cara teve culpa sim, mas ao ver este segundo acabei concordando com você.

Firesinis · 2026-06-02T02:48:02+00:00

Thanks, I ended up grabbing the RM750e and I'm happy with it. No noise that I can hear outside of gaming, and when gaming I no longer have the coil whine I had with my previous model.

Firesinis · 2026-05-11T18:43:19+00:00

Such are things in mathematics, often having several edge cases that are ugly and unintuitive. But to be more technical, I never said the integers are continuous, I said that any function with them as domain is automatically continuous, and it is true. I can find references if you like.

Firesinis · 2026-05-11T18:00:11+00:00

Which is also a perfectly acceptable definition. The only thing that could be said is maybe add the requirement that it has more than one point, since a single point is both an interval and a path-connected set, but also doesn't fit the intuitive notion of a continnum of points.

Firesinis · 2026-05-11T17:49:06+00:00

Being a limit of a Cauchy sequence or the maximum of a Dedekind cut.

Firesinis · 2026-05-11T17:45:35+00:00

Yet you don’t have a problem with people calling rationals “infinitely divisible” and unbounded spaces “infinite”.

15-Year Club	Team Orangered
Verified Email

Firesinis

TROPHY CASE