New posts in quadratic-forms

Proving an inequality with Cauchy-Schwarz

linear-algebra inequality hilbert-spaces quadratic-forms cauchy-schwarz-inequality

Show that $M = \{(x,y) \in \mathbb{R}^p \times \mathbb{R}^q : \lvert x \rvert = \lvert y \rvert \neq 0 \}$ is connected for $p,q \geq 2$

connectedness quadratic-forms path-connected

Parametrization of $x^2+ay^2=z^k$, where $\gcd(x,y,z)=1$

diophantine-equations quadratic-forms

What are all the concordant forms $n$ such that $a^2+b^2 = c^2,\,a^2+nb^2=d^2$ for $n<1000$?

diophantine-equations quadratic-forms computational-mathematics

Finding the vertex of an elliptic cone

geometry algebra-precalculus quadratic-forms

Help solving $ax^2+by^2+cz^2+dxy+exz+fzy=0$ where $(x_0,y_0,z_0)$ is a known integral solution

polynomials diophantine-equations quadratic-forms

If $p$ is prime, then $x^2 +5y^2 = p \iff p\equiv 1,9 $ mod $(20)$.

number-theory elementary-number-theory algebraic-number-theory quadratic-forms quadratic-residues

Derive the Quadratic Equation

polynomials quadratic-forms

If $[L:k]$ is odd, $f$ quadratic form over $k$, then $\exists$ zero in $k$ when $\exists$ zero in $L$

abstract-algebra field-theory quadratic-forms

Simultaneously vanishing quadratic forms

linear-algebra matrices systems-of-equations quadratic-forms

Intersection of cones tangent to a common sphere

geometry algebraic-geometry projective-geometry quadratic-forms

Analog of Vandermonde determinant for fitting a quadratic form?

linear-algebra geometry algebraic-geometry interpolation quadratic-forms

Meaning of $x^T A x$

linear-algebra matrices eigenvalues-eigenvectors quadratic-forms positive-semidefinite

maximal linear subspaces contained in the cone over the Clifford torus.

algebraic-geometry differential-geometry quadratic-forms

Representations of a ternary quadratic form, modular forms of wheight 3/2 and Eisenstein series

number-theory diophantine-equations quadratic-forms modular-forms

A Pell equation inside a Pell equation

number-theory elementary-number-theory quadratic-forms

Lower bound on quadratic form

linear-algebra matrices quadratic-forms positive-definite

Diagonalization of a symmetric matrix over algebraically closed field

linear-algebra quadratic-forms bilinear-form

Generalizing the 290 theorem.

number-theory quadratic-forms integer-lattices

What's the use of quadratic forms?

linear-algebra vector-spaces quadratic-forms