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comment Reference Request: Regge Symmetry “Angle-Edge” Duality
I believe Bob Marley is a feasible reference to what you're looking for.
Jul
3
revised How to get rid of the term with $xy$?
added 11 characters in body
Jul
3
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.
Jul
3
revised How to get rid of the term with $xy$?
added 292 characters in body
Jul
3
comment How to get rid of the term with $xy$?
I need to do a change of variable such that $xy=0$, right?
Jul
3
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.
Jul
3
comment How to get rid of the term with $xy$?
@r9m There are two matrixes. This one you mentioned and: $$\begin{pmatrix} {x}&{y}&{1} \end{pmatrix}\begin{pmatrix} {a}&{b/2}&{d/2}\\ {b/2}&{c}&{e/2}\\ {d/2}&{e/2}&{f} \end{pmatrix}\begin{pmatrix} {x}\\ {y}\\ {z} \end{pmatrix}$$
Jul
3
asked How to get rid of the term with $xy$?
Jul
3
revised Should the expanded expression of a quadratic form be equals to It's original expression?
added 171 characters in body
Jul
3
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.
Jul
3
revised Should the expanded expression of a quadratic form be equals to It's original expression?
deleted 3 characters in body
Jul
3
asked Should the expanded expression of a quadratic form be equals to It's original expression?
Jul
3
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.
Jul
2
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.
Jul
2
asked Where are these choices of $A',B',C'$ for this quadratic form?
Jul
2
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.
Jul
1
revised What is the definition of axiom (mathematically speaking)
added 229 characters in body
Jul
1
accepted Why $\int_c^{x+h}f(t) dt-\int_c^x f(t) dt = A(x+h)-A(x)$?
Jul
1
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.
Jul
1
asked When should I shift $a$ and $b$ in $\cfrac{x^2}{a^2}+\cfrac{y^2}{b^2}=1$?