New posts in quadratic-forms

What's a BETTER way to see the Gauss's composition law for binary quadratic forms?

number-theory algebraic-number-theory quadratic-forms

vector subset problem for linear approximation

linear-algebra combinatorics convex-optimization linear-programming quadratic-forms

Ternary Quadratic Forms

elementary-number-theory quadratic-forms

Why do positive definite matrices have to be symmetric? [duplicate]

matrices quadratic-forms positive-definite symmetric-matrices

How to factor the quadratic polynomial $2x^2-5xy-y^2$?

algebra-precalculus polynomials quadratics factoring quadratic-forms

Quadratic Diophantine Equation $x^2 + axy + y^2 = z^2$

diophantine-equations quadratic-forms

Elementary proof that $2x^2+xy+3y^2$ represents infinitely many primes?

number-theory prime-numbers quadratic-forms

Why do we assume that a matrix in quadratic form is Symmetric?

linear-algebra matrices quadratic-forms

Isotropy over $p$-adic numbers

p-adic-number-theory quadratic-forms

Write $(x^2 + y^2 + z^2)^2 - 3 ( x^3 y + y^3 z + z^3 x)$ as a sum of (three) squares of quadratic forms

matrices polynomials optimization quadratic-forms sum-of-squares-method

Show $15x^{2} - 7y^{2} = 9$ has no integer solutions

diophantine-equations quadratic-forms

How to solve inhomogeneous quadratic forms in integers?

number-theory diophantine-equations quadratic-forms

Differentiate $f(x)=x^TAx$

matrices multivariable-calculus derivatives quadratic-forms

How to calculate the gradient of $x^T A x$? [duplicate]

matrices multivariable-calculus derivatives differential-forms quadratic-forms

Finding integers of the form $3x^2 + xy - 5y^2$ where $x$ and $y$ are integers, using diagram via arithmetic progression

elementary-number-theory quadratic-forms

Discrepancy in derivative of quadratic form

calculus linear-algebra derivatives quadratic-forms

Derivative of Quadratic Form

matrices multivariable-calculus derivatives matrix-calculus quadratic-forms

Small integral representation as $x^2-2y^2$ in Pell's equation

arithmetic algebraic-number-theory quadratic-forms pell-type-equations

Find the transitional matrix that would transform this form to a diagonal form.

linear-algebra quadratic-forms

Meaning of the identity $\det(A+B)+\text{tr}(AB) = \det(A)+\det(B) + \text{tr}(A)\text{tr}(B)$ (in dimension $2$)

linear-algebra reference-request determinant quadratic-forms trace